commit ae7cbcc43b ("ASoC: samsung: tm2_wm5110: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit ae7cbcc43b ("ASoC: samsung: tm2_wm5110: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit a555b6a959 ("ASoC: samsung: snow: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit a555b6a959 ("ASoC: samsung: snow: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit d815e0f08f ("ASoC: samsung: smdk_wm8994: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit d815e0f08f ("ASoC: samsung: smdk_wm8994: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 33949eb501 ("ASoC: samsung: arndale_rt5631: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 33949eb501 ("ASoC: samsung: arndale_rt5631: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 27a37973a6 ("ASoC: rockchip: rockchip_rt5645: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 27a37973a6 ("ASoC: rockchip: rockchip_rt5645: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 7df405ae58 ("ASoC: rockchip: rockchip_max98090: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 7df405ae58 ("ASoC: rockchip: rockchip_max98090: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 9c21e82c16 ("ASoC: rockchip: rk3288_hdmi_analog: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 9c21e82c16 ("ASoC: rockchip: rk3288_hdmi_analog: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 3caf11fa88 ("ASoC: qcom: storm: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 3caf11fa88 ("ASoC: qcom: storm: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 5646843879 ("ASoC: qcom: apq8016_sbc: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 5646843879 ("ASoC: qcom: apq8016_sbc: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 5f92229d18 ("ASoC: mxs: mxs-sgtl5000: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 5f92229d18 ("ASoC: mxs: mxs-sgtl5000: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 717f163317 ("ASoC: kirkwood: armada-370-db: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 717f163317 ("ASoC: kirkwood: armada-370-db: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit d8893261a7 ("ASoC: fsl: imx-audmix: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit d8893261a7 ("ASoC: fsl: imx-audmix: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 014f07ca1c ("ASoC: fsl: imx-spdif: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 014f07ca1c ("ASoC: fsl: imx-spdif: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 82bf78ca49 ("ASoC: fsl: imx-sgtl5000: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 82bf78ca49 ("ASoC: fsl: imx-sgtl5000: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 577cf50d4d ("ASoC: fsl: imx-es8328: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 577cf50d4d ("ASoC: fsl: imx-es8328: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit e57a4c2f15 ("ASoC: fsl: fsl-asoc-card: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit e57a4c2f15 ("ASoC: fsl: fsl-asoc-card: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 2058ea1c4f ("ASoC: fsl: eukrea-tlv320: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 2058ea1c4f ("ASoC: fsl: eukrea-tlv320: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 655368dfc7 ("ASoC: atmel: tse850-pcm5142: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 655368dfc7 ("ASoC: atmel: tse850-pcm5142: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit ced5b08020 ("ASoC: atmel: sam9x5_wm8731: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit ced5b08020 ("ASoC: atmel: sam9x5_wm8731: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit bfc7938e58 ("ASoC: atmel: sam9g20_wm8731: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit bfc7938e58 ("ASoC: atmel: sam9g20_wm8731: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 318ebbe806 ("ASoC: atmel: mikroe-proto: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 318ebbe806 ("ASoC: atmel: mikroe-proto: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 3609750e9d ("ASoC: atmel: atmel_wm8904: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 3609750e9d ("ASoC: atmel: atmel_wm8904: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 7baf32e164 ("ASoC: atmel: atmel-pdmic: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 7baf32e164 ("ASoC: atmel: atmel-pdmic: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 02602401e5 ("ASoC: atmel: atmel-classd: don't select
unnecessary Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 02602401e5 ("ASoC: atmel: atmel-classd: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
commit 6c6de1c9e2 ("ASoC: vc4: vc4_hdmi: don't select unnecessary
Platform")
Current ALSA SoC avoid to add duplicate component to rtd,
and this driver was selecting CPU component as Platform component.
Thus, above patch removed Platform settings from this driver,
because it assumed these are same component.
But, some CPU driver is using generic DMAEngine, in such case, both
CPU component and Platform component will have same of_node/name.
In other words, there are some components which are different but
have same of_node/name.
In such case, Card driver definitely need to select Platform even
though it is same as CPU.
It is depends on CPU driver, but is difficult to know it from Card driver.
This patch reverts above patch.
Fixes: commit 6c6de1c9e2 ("ASoC: vc4: vc4_hdmi: don't select unnecessary Platform")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently when a kstrdup fails the error exit paths don't free
the allocations for sm, se and sbe. This can be fixed by assigning
kc[i].private_value to these before doing the ksrtdup so that the error
exit path will be able to free these objects.
Addresses-Coverity: ("Resource leak")
Fixes: 9f90af3a99 ("ASoC: topology: Consolidate and fix asoc_tplg_dapm_widget_*_create flow")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
I'm not entirely sure why this is, but for some reason:
921935dc64 ("drm/amd/powerplay: enforce display related settings only on needed")
Breaks runtime PM resume on the Radeon PRO WX 3100 (Lexa) in one the
pre-production laptops I have. The issue manifests as the following
messages in dmesg:
[drm] UVD and UVD ENC initialized successfully.
amdgpu 0000:3b:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring vce1 test failed (-110)
[drm:amdgpu_device_ip_resume_phase2 [amdgpu]] *ERROR* resume of IP block <vce_v3_0> failed -110
[drm:amdgpu_device_resume [amdgpu]] *ERROR* amdgpu_device_ip_resume failed (-110).
And happens after about 6-10 runtime PM suspend/resume cycles (sometimes
sooner, if you're lucky!). Unfortunately I can't seem to pin down
precisely which part in psm_adjust_power_state_dynamic that is causing
the issue, but not skipping the display setting setup seems to fix it.
Hopefully if there is a better fix for this, this patch will spark
discussion around it.
Fixes: 921935dc64 ("drm/amd/powerplay: enforce display related settings only on needed")
Cc: Evan Quan <evan.quan@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Rex Zhu <Rex.Zhu@amd.com>
Cc: Likun Gao <Likun.Gao@amd.com>
Cc: <stable@vger.kernel.org> # v5.1+
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Shifting signed 32-bit value by 31 bits is undefined. Changing most
significant bit to unsigned.
Signed-off-by: Jiunn Chang <c0d1n61at3@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There's no need to check the parent of the remote device to check
whether it is available or not, the remote is the device itself.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Rather than having a nested set of for_each_child_of_node() walkers,
use the graph walker to iterate through the endpoints for CRTCs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
If there's a simple-framebuffer carried over from boot firmware, it's going
to stop working once we setup the LCDC for use via DRM. Kick it off from
the hardware.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
In reboot tests on several devices we were seeing a "use after free"
when slub_debug or KASAN was enabled. The kernel complained about:
Unable to handle kernel paging request at virtual address 6b6b6c2b
...which is a classic sign of use after free under slub_debug. The
stack crawl in kgdb looked like:
0 test_bit (addr=<optimized out>, nr=<optimized out>)
1 bfq_bfqq_busy (bfqq=<optimized out>)
2 bfq_select_queue (bfqd=<optimized out>)
3 __bfq_dispatch_request (hctx=<optimized out>)
4 bfq_dispatch_request (hctx=<optimized out>)
5 0xc056ef00 in blk_mq_do_dispatch_sched (hctx=0xed249440)
6 0xc056f728 in blk_mq_sched_dispatch_requests (hctx=0xed249440)
7 0xc0568d24 in __blk_mq_run_hw_queue (hctx=0xed249440)
8 0xc0568d94 in blk_mq_run_work_fn (work=<optimized out>)
9 0xc024c5c4 in process_one_work (worker=0xec6d4640, work=0xed249480)
10 0xc024cff4 in worker_thread (__worker=0xec6d4640)
Digging in kgdb, it could be found that, though bfqq looked fine,
bfqq->bic had been freed.
Through further digging, I postulated that perhaps it is illegal to
access a "bic" (AKA an "icq") after bfq_exit_icq() had been called
because the "bic" can be freed at some point in time after this call
is made. I confirmed that there certainly were cases where the exact
crashing code path would access the "bic" after bfq_exit_icq() had
been called. Sspecifically I set the "bfqq->bic" to (void *)0x7 and
saw that the bic was 0x7 at the time of the crash.
To understand a bit more about why this crash was fairly uncommon (I
saw it only once in a few hundred reboots), you can see that much of
the time bfq_exit_icq_fbqq() fully frees the bfqq and thus it can't
access the ->bic anymore. The only case it doesn't is if
bfq_put_queue() sees a reference still held.
However, even in the case when bfqq isn't freed, the crash is still
rare. Why? I tracked what happened to the "bic" after the exit
routine. It doesn't get freed right away. Rather,
put_io_context_active() eventually called put_io_context() which
queued up freeing on a workqueue. The freeing then actually happened
later than that through call_rcu(). Despite all these delays, some
extra debugging showed that all the hoops could be jumped through in
time and the memory could be freed causing the original crash. Phew!
To make a long story short, assuming it truly is illegal to access an
icq after the "exit_icq" callback is finished, this patch is needed.
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now we have counters for how many times jouranl is reclaimed, how many
times cached dirty btree nodes are flushed, but we don't know how many
jouranl buckets are really reclaimed.
This patch adds reclaimed_journal_buckets into struct cache_set, this
is an increasing only counter, to tell how many journal buckets are
reclaimed since cache set runs. From all these three counters (reclaim,
reclaimed_journal_buckets, flush_write), we can have idea how well
current journal space reclaim code works.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch improves performance for btree_flush_write() in following
ways,
- Use another spinlock journal.flush_write_lock to replace the very
hot journal.lock. We don't have to use journal.lock here, selecting
candidate btree nodes takes a lot of time, hold journal.lock here will
block other jouranling threads and drop the overall I/O performance.
- Only select flushing btree node from c->btree_cache list. When the
machine has a large system memory, mca cache may have a huge number of
cached btree nodes. Iterating all the cached nodes will take a lot
of CPU time, and most of the nodes on c->btree_cache_freeable and
c->btree_cache_freed lists are cleared and have need to flush. So only
travel mca list c->btree_cache to select flushing btree node should be
enough for most of the cases.
- Don't iterate whole c->btree_cache list, only reversely select first
BTREE_FLUSH_NR btree nodes to flush. Iterate all btree nodes from
c->btree_cache and select the oldest journal pin btree nodes consumes
huge number of CPU cycles if the list is huge (push and pop a node
into/out of a heap is expensive). The last several dirty btree nodes
on the tail of c->btree_cache list are earlest allocated and cached
btree nodes, they are relative to the oldest journal pin btree nodes.
Therefore only flushing BTREE_FLUSH_NR btree nodes from tail of
c->btree_cache probably includes the oldest journal pin btree nodes.
In my testing, the above change decreases 50%+ CPU consumption when
journal space is full. Some times IOPS drops to 0 for 5-8 seconds,
comparing blocking I/O for 120+ seconds in previous code, this is much
better. Maybe there is room to improve in future, but at this momment
the fix looks fine and performs well in my testing.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is a race between mca_reap(), btree_node_free() and journal code
btree_flush_write(), which results very rare and strange deadlock or
panic and are very hard to reproduce.
Let me explain how the race happens. In btree_flush_write() one btree
node with oldest journal pin is selected, then it is flushed to cache
device, the select-and-flush is a two steps operation. Between these two
steps, there are something may happen inside the race window,
- The selected btree node was reaped by mca_reap() and allocated to
other requesters for other btree node.
- The slected btree node was selected, flushed and released by mca
shrink callback bch_mca_scan().
When btree_flush_write() tries to flush the selected btree node, firstly
b->write_lock is held by mutex_lock(). If the race happens and the
memory of selected btree node is allocated to other btree node, if that
btree node's write_lock is held already, a deadlock very probably
happens here. A worse case is the memory of the selected btree node is
released, then all references to this btree node (e.g. b->write_lock)
will trigger NULL pointer deference panic.
This race was introduced in commit cafe563591 ("bcache: A block layer
cache"), and enlarged by commit c4dc2497d5 ("bcache: fix high CPU
occupancy during journal"), which selected 128 btree nodes and flushed
them one-by-one in a quite long time period.
Such race is not easy to reproduce before. On a Lenovo SR650 server with
48 Xeon cores, and configure 1 NVMe SSD as cache device, a MD raid0
device assembled by 3 NVMe SSDs as backing device, this race can be
observed around every 10,000 times btree_flush_write() gets called. Both
deadlock and kernel panic all happened as aftermath of the race.
The idea of the fix is to add a btree flag BTREE_NODE_journal_flush. It
is set when selecting btree nodes, and cleared after btree nodes
flushed. Then when mca_reap() selects a btree node with this bit set,
this btree node will be skipped. Since mca_reap() only reaps btree node
without BTREE_NODE_journal_flush flag, such race is avoided.
Once corner case should be noticed, that is btree_node_free(). It might
be called in some error handling code path. For example the following
code piece from btree_split(),
2149 err_free2:
2150 bkey_put(b->c, &n2->key);
2151 btree_node_free(n2);
2152 rw_unlock(true, n2);
2153 err_free1:
2154 bkey_put(b->c, &n1->key);
2155 btree_node_free(n1);
2156 rw_unlock(true, n1);
At line 2151 and 2155, the btree node n2 and n1 are released without
mac_reap(), so BTREE_NODE_journal_flush also needs to be checked here.
If btree_node_free() is called directly in such error handling path,
and the selected btree node has BTREE_NODE_journal_flush bit set, just
delay for 1 us and retry again. In this case this btree node won't
be skipped, just retry until the BTREE_NODE_journal_flush bit cleared,
and free the btree node memory.
Fixes: cafe563591 ("bcache: A block layer cache")
Signed-off-by: Coly Li <colyli@suse.de>
Reported-and-tested-by: kbuild test robot <lkp@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In struct cache_set, retry_flush_write is added for commit c4dc2497d5
("bcache: fix high CPU occupancy during journal") which is reverted in
previous patch.
Now it is useless anymore, and this patch removes it from bcache code.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When accessing or modifying BTREE_NODE_dirty bit, it is not always
necessary to acquire b->write_lock. In bch_btree_cache_free() and
mca_reap() acquiring b->write_lock is necessary, and this patch adds
comments to explain why mutex_lock(&b->write_lock) is necessary for
checking or clearing BTREE_NODE_dirty bit there.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In bch_btree_cache_free() and btree_node_free(), BTREE_NODE_dirty is
always set no matter btree node is dirty or not. The code looks like
this,
if (btree_node_dirty(b))
btree_complete_write(b, btree_current_write(b));
clear_bit(BTREE_NODE_dirty, &b->flags);
Indeed if btree_node_dirty(b) returns false, it means BTREE_NODE_dirty
bit is cleared, then it is unnecessary to clear the bit again.
This patch only clears BTREE_NODE_dirty when btree_node_dirty(b) is
true (the bit is set), to save a few CPU cycles.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit c4dc2497d5.
This patch enlarges a race between normal btree flush code path and
flush_btree_write(), which causes deadlock when journal space is
exhausted. Reverts this patch makes the race window from 128 btree
nodes to only 1 btree nodes.
Fixes: c4dc2497d5 ("bcache: fix high CPU occupancy during journal")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Tang Junhui <tang.junhui.linux@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit 6268dc2c47.
This patch depends on commit c4dc2497d5 ("bcache: fix high CPU
occupancy during journal") which is reverted in previous patch. So
revert this one too.
Fixes: 6268dc2c47 ("bcache: free heap cache_set->flush_btree in bch_journal_free")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When cache set starts, bch_btree_check() will check all bkeys on cache
device by calculating the checksum. This operation will consume a huge
number of system memory if there are a lot of data cached. Since bcache
uses its own mca cache to maintain all its read-in btree nodes, and only
releases the cache space when system memory manage code starts to shrink
caches. Then before memory manager code to call the mca cache shrinker
callback, bcache mca cache will compete memory resource with user space
application, which may have nagive effect to performance of user space
workloads (e.g. data base, or I/O service of distributed storage node).
This patch tries to call bcache mca shrinker routine to proactively
release mca cache memory, to decrease the memory pressure of system and
avoid negative effort of the overall system I/O performance.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In journal_read_bucket() when setting ja->seq[bucket_index], there might
be potential case that a later non-maximum overwrites a better sequence
number to ja->seq[bucket_index]. This patch adds a check to make sure
that ja->seq[bucket_index] will be only set a new value if it is bigger
then current value.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch adds more code comments in journal_read_bucket(), this is an
effort to make the code to be more understandable.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When enable lockdep and reboot system with a writeback mode bcache
device, the following potential deadlock warning is reported by lockdep
engine.
[ 101.536569][ T401] kworker/2:2/401 is trying to acquire lock:
[ 101.538575][ T401] 00000000bbf6e6c7 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0
[ 101.542054][ T401]
[ 101.542054][ T401] but task is already holding lock:
[ 101.544587][ T401] 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[ 101.548386][ T401]
[ 101.548386][ T401] which lock already depends on the new lock.
[ 101.548386][ T401]
[ 101.551874][ T401]
[ 101.551874][ T401] the existing dependency chain (in reverse order) is:
[ 101.555000][ T401]
[ 101.555000][ T401] -> #1 ((work_completion)(&cl->work)#2){+.+.}:
[ 101.557860][ T401] process_one_work+0x277/0x640
[ 101.559661][ T401] worker_thread+0x39/0x3f0
[ 101.561340][ T401] kthread+0x125/0x140
[ 101.562963][ T401] ret_from_fork+0x3a/0x50
[ 101.564718][ T401]
[ 101.564718][ T401] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}:
[ 101.567701][ T401] lock_acquire+0xb4/0x1c0
[ 101.569651][ T401] flush_workqueue+0xae/0x4c0
[ 101.571494][ T401] drain_workqueue+0xa9/0x180
[ 101.573234][ T401] destroy_workqueue+0x17/0x250
[ 101.575109][ T401] cached_dev_free+0x44/0x120 [bcache]
[ 101.577304][ T401] process_one_work+0x2a4/0x640
[ 101.579357][ T401] worker_thread+0x39/0x3f0
[ 101.581055][ T401] kthread+0x125/0x140
[ 101.582709][ T401] ret_from_fork+0x3a/0x50
[ 101.584592][ T401]
[ 101.584592][ T401] other info that might help us debug this:
[ 101.584592][ T401]
[ 101.588355][ T401] Possible unsafe locking scenario:
[ 101.588355][ T401]
[ 101.590974][ T401] CPU0 CPU1
[ 101.592889][ T401] ---- ----
[ 101.594743][ T401] lock((work_completion)(&cl->work)#2);
[ 101.596785][ T401] lock((wq_completion)bcache_writeback_wq);
[ 101.600072][ T401] lock((work_completion)(&cl->work)#2);
[ 101.602971][ T401] lock((wq_completion)bcache_writeback_wq);
[ 101.605255][ T401]
[ 101.605255][ T401] *** DEADLOCK ***
[ 101.605255][ T401]
[ 101.608310][ T401] 2 locks held by kworker/2:2/401:
[ 101.610208][ T401] #0: 00000000cf2c7d17 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640
[ 101.613709][ T401] #1: 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[ 101.617480][ T401]
[ 101.617480][ T401] stack backtrace:
[ 101.619539][ T401] CPU: 2 PID: 401 Comm: kworker/2:2 Tainted: G W 5.2.0-rc4-lp151.20-default+ #1
[ 101.623225][ T401] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[ 101.627210][ T401] Workqueue: events cached_dev_free [bcache]
[ 101.629239][ T401] Call Trace:
[ 101.630360][ T401] dump_stack+0x85/0xcb
[ 101.631777][ T401] print_circular_bug+0x19a/0x1f0
[ 101.633485][ T401] __lock_acquire+0x16cd/0x1850
[ 101.635184][ T401] ? __lock_acquire+0x6a8/0x1850
[ 101.636863][ T401] ? lock_acquire+0xb4/0x1c0
[ 101.638421][ T401] ? find_held_lock+0x34/0xa0
[ 101.640015][ T401] lock_acquire+0xb4/0x1c0
[ 101.641513][ T401] ? flush_workqueue+0x87/0x4c0
[ 101.643248][ T401] flush_workqueue+0xae/0x4c0
[ 101.644832][ T401] ? flush_workqueue+0x87/0x4c0
[ 101.646476][ T401] ? drain_workqueue+0xa9/0x180
[ 101.648303][ T401] drain_workqueue+0xa9/0x180
[ 101.649867][ T401] destroy_workqueue+0x17/0x250
[ 101.651503][ T401] cached_dev_free+0x44/0x120 [bcache]
[ 101.653328][ T401] process_one_work+0x2a4/0x640
[ 101.655029][ T401] worker_thread+0x39/0x3f0
[ 101.656693][ T401] ? process_one_work+0x640/0x640
[ 101.658501][ T401] kthread+0x125/0x140
[ 101.660012][ T401] ? kthread_create_worker_on_cpu+0x70/0x70
[ 101.661985][ T401] ret_from_fork+0x3a/0x50
[ 101.691318][ T401] bcache: bcache_device_free() bcache0 stopped
Here is how the above potential deadlock may happen in reboot/shutdown
code path,
1) bcache_reboot() is called firstly in the reboot/shutdown code path,
then in bcache_reboot(), bcache_device_stop() is called.
2) bcache_device_stop() sets BCACHE_DEV_CLOSING on d->falgs, then call
closure_queue(&d->cl) to invoke cached_dev_flush(). And in turn
cached_dev_flush() calls cached_dev_free() via closure_at()
3) In cached_dev_free(), after stopped writebach kthread
dc->writeback_thread, the kwork dc->writeback_write_wq is stopping by
destroy_workqueue().
4) Inside destroy_workqueue(), drain_workqueue() is called. Inside
drain_workqueue(), flush_workqueue() is called. Then wq->lockdep_map
is acquired by lock_map_acquire() in flush_workqueue(). After the
lock acquired the rest part of flush_workqueue() just wait for the
workqueue to complete.
5) Now we look back at writeback thread routine bch_writeback_thread(),
in the main while-loop, write_dirty() is called via continue_at() in
read_dirty_submit(), which is called via continue_at() in while-loop
level called function read_dirty(). Inside write_dirty() it may be
re-called on workqueeu dc->writeback_write_wq via continue_at().
It means when the writeback kthread is stopped in cached_dev_free()
there might be still one kworker queued on dc->writeback_write_wq
to execute write_dirty() again.
6) Now this kworker is scheduled on dc->writeback_write_wq to run by
process_one_work() (which is called by worker_thread()). Before
calling the kwork routine, wq->lockdep_map is acquired.
7) But wq->lockdep_map is acquired already in step 4), so a A-A lock
(lockdep terminology) scenario happens.
Indeed on multiple cores syatem, the above deadlock is very rare to
happen, just as the code comments in process_one_work() says,
2263 * AFAICT there is no possible deadlock scenario between the
2264 * flush_work() and complete() primitives (except for
single-threaded
2265 * workqueues), so hiding them isn't a problem.
But it is still good to fix such lockdep warning, even no one running
bcache on single core system.
The fix is simple. This patch solves the above potential deadlock by,
- Do not destroy workqueue dc->writeback_write_wq in cached_dev_free().
- Flush and destroy dc->writeback_write_wq in writebach kthread routine
bch_writeback_thread(), where after quit the thread main while-loop
and before cached_dev_put() is called.
By this fix, dc->writeback_write_wq will be stopped and destroy before
the writeback kthread stopped, so the chance for a A-A locking on
wq->lockdep_map is disappeared, such A-A deadlock won't happen
any more.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When enable lockdep engine, a lockdep warning can be observed when
reboot or shutdown system,
[ 3142.764557][ T1] bcache: bcache_reboot() Stopping all devices:
[ 3142.776265][ T2649]
[ 3142.777159][ T2649] ======================================================
[ 3142.780039][ T2649] WARNING: possible circular locking dependency detected
[ 3142.782869][ T2649] 5.2.0-rc4-lp151.20-default+ #1 Tainted: G W
[ 3142.785684][ T2649] ------------------------------------------------------
[ 3142.788479][ T2649] kworker/3:67/2649 is trying to acquire lock:
[ 3142.790738][ T2649] 00000000aaf02291 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0
[ 3142.794678][ T2649]
[ 3142.794678][ T2649] but task is already holding lock:
[ 3142.797402][ T2649] 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache]
[ 3142.801462][ T2649]
[ 3142.801462][ T2649] which lock already depends on the new lock.
[ 3142.801462][ T2649]
[ 3142.805277][ T2649]
[ 3142.805277][ T2649] the existing dependency chain (in reverse order) is:
[ 3142.808902][ T2649]
[ 3142.808902][ T2649] -> #2 (&bch_register_lock){+.+.}:
[ 3142.812396][ T2649] __mutex_lock+0x7a/0x9d0
[ 3142.814184][ T2649] cached_dev_free+0x17/0x120 [bcache]
[ 3142.816415][ T2649] process_one_work+0x2a4/0x640
[ 3142.818413][ T2649] worker_thread+0x39/0x3f0
[ 3142.820276][ T2649] kthread+0x125/0x140
[ 3142.822061][ T2649] ret_from_fork+0x3a/0x50
[ 3142.823965][ T2649]
[ 3142.823965][ T2649] -> #1 ((work_completion)(&cl->work)#2){+.+.}:
[ 3142.827244][ T2649] process_one_work+0x277/0x640
[ 3142.829160][ T2649] worker_thread+0x39/0x3f0
[ 3142.830958][ T2649] kthread+0x125/0x140
[ 3142.832674][ T2649] ret_from_fork+0x3a/0x50
[ 3142.834915][ T2649]
[ 3142.834915][ T2649] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}:
[ 3142.838121][ T2649] lock_acquire+0xb4/0x1c0
[ 3142.840025][ T2649] flush_workqueue+0xae/0x4c0
[ 3142.842035][ T2649] drain_workqueue+0xa9/0x180
[ 3142.844042][ T2649] destroy_workqueue+0x17/0x250
[ 3142.846142][ T2649] cached_dev_free+0x52/0x120 [bcache]
[ 3142.848530][ T2649] process_one_work+0x2a4/0x640
[ 3142.850663][ T2649] worker_thread+0x39/0x3f0
[ 3142.852464][ T2649] kthread+0x125/0x140
[ 3142.854106][ T2649] ret_from_fork+0x3a/0x50
[ 3142.855880][ T2649]
[ 3142.855880][ T2649] other info that might help us debug this:
[ 3142.855880][ T2649]
[ 3142.859663][ T2649] Chain exists of:
[ 3142.859663][ T2649] (wq_completion)bcache_writeback_wq --> (work_completion)(&cl->work)#2 --> &bch_register_lock
[ 3142.859663][ T2649]
[ 3142.865424][ T2649] Possible unsafe locking scenario:
[ 3142.865424][ T2649]
[ 3142.868022][ T2649] CPU0 CPU1
[ 3142.869885][ T2649] ---- ----
[ 3142.871751][ T2649] lock(&bch_register_lock);
[ 3142.873379][ T2649] lock((work_completion)(&cl->work)#2);
[ 3142.876399][ T2649] lock(&bch_register_lock);
[ 3142.879727][ T2649] lock((wq_completion)bcache_writeback_wq);
[ 3142.882064][ T2649]
[ 3142.882064][ T2649] *** DEADLOCK ***
[ 3142.882064][ T2649]
[ 3142.885060][ T2649] 3 locks held by kworker/3:67/2649:
[ 3142.887245][ T2649] #0: 00000000e774cdd0 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640
[ 3142.890815][ T2649] #1: 00000000f7df89da ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[ 3142.894884][ T2649] #2: 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache]
[ 3142.898797][ T2649]
[ 3142.898797][ T2649] stack backtrace:
[ 3142.900961][ T2649] CPU: 3 PID: 2649 Comm: kworker/3:67 Tainted: G W 5.2.0-rc4-lp151.20-default+ #1
[ 3142.904789][ T2649] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[ 3142.909168][ T2649] Workqueue: events cached_dev_free [bcache]
[ 3142.911422][ T2649] Call Trace:
[ 3142.912656][ T2649] dump_stack+0x85/0xcb
[ 3142.914181][ T2649] print_circular_bug+0x19a/0x1f0
[ 3142.916193][ T2649] __lock_acquire+0x16cd/0x1850
[ 3142.917936][ T2649] ? __lock_acquire+0x6a8/0x1850
[ 3142.919704][ T2649] ? lock_acquire+0xb4/0x1c0
[ 3142.921335][ T2649] ? find_held_lock+0x34/0xa0
[ 3142.923052][ T2649] lock_acquire+0xb4/0x1c0
[ 3142.924635][ T2649] ? flush_workqueue+0x87/0x4c0
[ 3142.926375][ T2649] flush_workqueue+0xae/0x4c0
[ 3142.928047][ T2649] ? flush_workqueue+0x87/0x4c0
[ 3142.929824][ T2649] ? drain_workqueue+0xa9/0x180
[ 3142.931686][ T2649] drain_workqueue+0xa9/0x180
[ 3142.933534][ T2649] destroy_workqueue+0x17/0x250
[ 3142.935787][ T2649] cached_dev_free+0x52/0x120 [bcache]
[ 3142.937795][ T2649] process_one_work+0x2a4/0x640
[ 3142.939803][ T2649] worker_thread+0x39/0x3f0
[ 3142.941487][ T2649] ? process_one_work+0x640/0x640
[ 3142.943389][ T2649] kthread+0x125/0x140
[ 3142.944894][ T2649] ? kthread_create_worker_on_cpu+0x70/0x70
[ 3142.947744][ T2649] ret_from_fork+0x3a/0x50
[ 3142.970358][ T2649] bcache: bcache_device_free() bcache0 stopped
Here is how the deadlock happens.
1) bcache_reboot() calls bcache_device_stop(), then inside
bcache_device_stop() BCACHE_DEV_CLOSING bit is set on d->flags.
Then closure_queue(&d->cl) is called to invoke cached_dev_flush().
2) In cached_dev_flush(), cached_dev_free() is called by continu_at().
3) In cached_dev_free(), when stopping the writeback kthread of the
cached device by kthread_stop(), dc->writeback_thread will be waken
up to quite the kthread while-loop, then cached_dev_put() is called
in bch_writeback_thread().
4) Calling cached_dev_put() in writeback kthread may drop dc->count to
0, then dc->detach kworker is scheduled, which is initialized as
cached_dev_detach_finish().
5) Inside cached_dev_detach_finish(), the last line of code is to call
closure_put(&dc->disk.cl), which drops the last reference counter of
closrure dc->disk.cl, then the callback cached_dev_flush() gets
called.
Now cached_dev_flush() is called for second time in the code path, the
first time is in step 2). And again bch_register_lock will be acquired
again, and a A-A lock (lockdep terminology) is happening.
The root cause of the above A-A lock is in cached_dev_free(), mutex
bch_register_lock is held before stopping writeback kthread and other
kworkers. Fortunately now we have variable 'bcache_is_reboot', which may
prevent device registration or unregistration during reboot/shutdown
time, so it is unncessary to hold bch_register_lock such early now.
This is how this patch fixes the reboot/shutdown time A-A lock issue:
After moving mutex_lock(&bch_register_lock) to a later location where
before atomic_read(&dc->running) in cached_dev_free(), such A-A lock
problem can be solved without any reboot time registration race.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now there is variable bcache_is_reboot to prevent device register or
unregister during reboot, it is unncessary to still hold mutex lock
bch_register_lock before stopping writeback_rate_update kworker and
writeback kthread. And if the stopping kworker or kthread holding
bch_register_lock inside their routine (we used to have such problem
in writeback thread, thanks to Junhui Wang fixed it), it is very easy
to introduce deadlock during reboot/shutdown procedure.
Therefore in this patch, the location to acquire bch_register_lock is
moved to the location before calling calc_cached_dev_sectors(). Which
is later then original location in cached_dev_detach_finish().
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It is quite frequently to observe deadlock in bcache_reboot() happens
and hang the system reboot process. The reason is, in bcache_reboot()
when calling bch_cache_set_stop() and bcache_device_stop() the mutex
bch_register_lock is held. But in the process to stop cache set and
bcache device, bch_register_lock will be acquired again. If this mutex
is held here, deadlock will happen inside the stopping process. The
aftermath of the deadlock is, whole system reboot gets hung.
The fix is to avoid holding bch_register_lock for the following loops
in bcache_reboot(),
list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
bch_cache_set_stop(c);
list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
bcache_device_stop(&dc->disk);
A module range variable 'bcache_is_reboot' is added, it sets to true
in bcache_reboot(). In register_bcache(), if bcache_is_reboot is checked
to be true, reject the registration by returning -EBUSY immediately.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
