Add support for the PIO mode and mixed PIO/DMA mode support. The mixed
PIO/DMA is the default mode of operation. This shall leverage overhead
that the driver creates due to setting up DMA descriptors even for very
short transfers.
The current boundary between PIO/DMA 8 bytes, transfers shorter than 8
bytes are transfered by PIO, longer transfers use DMA. The performance
of write transfers remains unchanged, while there is a minor improvement
of read performance. Reading 16KB EEPROM with DMA-only operations gives
a read speed of 39.5KB/s, while with then new mixed-mode the speed is
blazing 40.6KB/s.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
err_cpufreq label is now used only once. It can be removed and related
code can be moved to the caller location.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
In i2c-s3c2410 driver probe, only s3c24xx_i2c_init() needs the I2C clock
to be enabled. Moving clk_prepare_enable() and clk_disable_unprepare()
calls to around this function simplifies the return path of probe call.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
i2c-s3c2410 driver is modified to use devm_clk_get()
and devm_request_irq(). This also simplifies the
return path in driver's probe.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
err_noclk label redirects to a simple return statement. Move the
return statement to the caller location and remove the label.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Amend the I2C nomadik pin controller to optionally take a pin control
handle and set the state of the pins to:
- "default" on boot, resume and before performing an i2c transfer
- "idle" after initial default, after resume default, and after each
i2c xfer
- "sleep" on suspend()
This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle, and for runtime cases inbetween
I2C transfers.
Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
NVIDIA's Tegra114 has following enhanced feature in i2c controller:
- Enable/disable control for per packet transfer complete interrupt.
Earlier SoCs could not disable this.
- Single clock source for standard/fast and HS mode clock speed.
The clock divisor for fast/standard mode is added into the i2c
controller to meet the HS and standard/fast mode of clock speed
from single source.
Add support for the above feature to make it functional on T114 SOCs.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Intel Lynxpoint has two I2C controllers. These controllers are enumerated
from ACPI namespace with IDs INT33C2 and INT33C3. Add support for these to
the I2C DesignWare platform driver.
This is based on the work of Dirk Brandewie.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
In order to save power the device should be put to low power states
whenever it is not being used. We implement this by enabling minimal
runtime PM support.
There isn't much to do for the device itself as it is disabled once the
last transfer is completed but subsystem/domain runtime PM hooks can save
more power by power gating the device etc.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
If IC_EMPTYFIFO_HOLD_MASTER_EN is set to one, the DesignWare I2C controller
doesn't generate STOP on the bus when the FIFO is empty. This violates the
rules of Linux I2C stack as it requires that the STOP is issued once the
i2c_transfer() is finished.
However, there is no way to detect this from the hardware registers, so we
must make sure that the STOP bit is always set once the last byte of the
last message is transferred.
This patch is based on the work of Dirk Brandewie.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
avoid these checkpatch.pl issues :
- ERROR: "foo * bar" should be "foo *bar"
- ERROR: switch and case should be at the same indent
- ERROR: "(foo*)" should be "(foo *)"
- ERROR: do not use assignment in if condition
- ERROR: space required before the open parenthesis '('
- WARNING: suspect code indent for conditional statements
- WARNING: quoted string split across lines
- WARNING: space prohibited between function name and open parenthesis '('
- WARNING: line over 80 characters
also add spaces around some "+", "=", "*"
Signed-off-by: Laurent Navet <laurent.navet@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
As the at24 driver is able handle a bunch of serial storage chips other than
EEPROMs this is now mentioned in Kconfig.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
i2c_smbus_process_call has no users in the kernel, so this can be
removed. Documentation for the same has been updated accordingly.
Fixes following sparse warning.
drivers/i2c/i2c-core.c:1871:5: warning: symbol 'i2c_smbus_process_call'
was not declared. Should it be static?
[wsa: updated the documentation]
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Pull ARM SoC fixes from Olof Johansson:
"Here's a long-pending fixes pull request for arm-soc (I didn't send
one in the -rc4 cycle).
The larger deltas are from:
- A fixup of error paths in the mvsdio driver
- Header file move for a driver that hadn't been properly converted
to multiplatform on i.MX, which was causing build failures when
included
- Device tree updates for at91 dealing mostly with their new pinctrl
setup merged in 3.8 and mistakes in those initial configs
The rest are the normal mix of small fixes all over the place; sunxi,
omap, imx, mvebu, etc, etc."
* tag 'fixes-for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (40 commits)
mfd: vexpress-sysreg: Don't skip initialization on probe
ARM: vexpress: Enable A7 cores in V2P-CA15_A7's Device Tree
ARM: vexpress: extend the MPIDR range used for pen release check
ARM: at91/dts: correct comment in at91sam9x5.dtsi for mii
ARM: at91/at91_dt_defconfig: add at91sam9n12 SoC to DT defconfig
ARM: at91/at91_dt_defconfig: remove memory specification to cmdline
ARM: at91/dts: add macb mii pinctrl config for kizbox
ARM: at91: rm9200: remake the BGA as default version
ARM: at91: fix gpios on i2c-gpio for RM9200 DT
ARM: at91/at91sam9x5 DTS: add SCK USART pins
ARM: at91/at91sam9x5 DTS: correct wrong PIO BANK values on u(s)arts
ARM: at91/at91-pinctrl documentation: fix typo and add some details
ARM: kirkwood: fix missing #interrupt-cells property
mmc: mvsdio: use devm_ API to simplify/correct error paths.
clk: mvebu/clk-cpu.c: fix memory leakage
ARM: OMAP2+: omap4-panda: add UART2 muxing for WiLink shared transport
ARM: OMAP2+: DT node Timer iteration fix
ARM: OMAP2+: Fix section warning for omap_init_ocp2scp()
ARM: OMAP2+: fix build break for omapdrm
ARM: OMAP2: Fix missing omap2xxx_clkt_vps_late_init function calls
...
Pull ACPI and power management fixes from Rafael Wysocki:
- Two cpuidle initialization fixes from Konrad Rzeszutek Wilk.
- cpufreq regression fixes for AMD processors from Borislav Petkov,
Stefan Bader, and Matthew Garrett.
- ACPI cpufreq fix from Thomas Schlichter.
- cpufreq and devfreq fixes related to incorrect usage of operating
performance points (OPP) framework and RCU from Nishanth Menon.
- APEI workaround for incorrect BIOS information from Lans Zhang.
* tag 'pm+acpi-for-3.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: Add module aliases for acpi-cpufreq
ACPI: Check MSR valid bit before using P-state frequencies
PM / devfreq: exynos4_bus: honor RCU lock usage
PM / devfreq: add locking documentation for recommended_opp
cpufreq: cpufreq-cpu0: use RCU locks around usage of OPP
cpufreq: OMAP: use RCU locks around usage of OPP
ACPI, APEI: Fixup incorrect 64-bit access width firmware bug
ACPI / processor: Get power info before updating the C-states
powernow-k8: Add a kconfig dependency on acpi-cpufreq
ACPI / cpuidle: Fix NULL pointer issues when cpuidle is disabled
intel_idle: Don't register CPU notifier if we are not running.
Pull regmap fixes from Mark Brown:
"One more oversight in the debugfs code was reported and fixed, plus a
documentation fix."
* tag 'regmap-fix-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: fix small typo in regmap_bulk_write comment
regmap: debugfs: Fix seeking from the cache
Pull slave-dmaengine fixes from Vinod Koul:
"A few fixes on slave dmanengine. There are trivial fixes in imx-dma,
tegra-dma & ioat driver"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dma: tegra: implement flags parameters for cyclic transfer
dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.
ioat: Fix DMA memory sync direction correct flag
From Pawel Moll:
- makes the V2P-CA15_A7 (a.k.a. TC2) work with 3.8 kernels
- improves vexpress-sysreg.c behaviour on arm64 platforms
* 'vexpress/fixes' of git://git.linaro.org/people/pawelmoll/linux:
mfd: vexpress-sysreg: Don't skip initialization on probe
ARM: vexpress: Enable A7 cores in V2P-CA15_A7's Device Tree
ARM: vexpress: extend the MPIDR range used for pen release check
The vexpress-sysreg driver does not have to be initialized
early, when the platform doesn't require this. Unfortunately
in such case it wasn't initialized correctly - master site
lookup and config bridge registration were missing. Fixed now.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
From Shawn Guo:
This is yet another critical imxfb fixes held off by absence of FB
maintainer for some time.
* tag 'imx-fixes-3.8-3' of git://git.linaro.org/people/shawnguo/linux-2.6:
video: imxfb: Do not crash on reboot
From Jason Cooper:
mvebu fixes for v3.8-rc5
- fix memory leak in mvebu/clk-cpu.c
- use devm_ to correct/simplify error paths in mvsdio
- add missing #interrupt-cells property in kirkwood
* tag 'mvebu_fixes_for_v3.8-rc5' of git://git.infradead.org/users/jcooper/linux:
ARM: kirkwood: fix missing #interrupt-cells property
mmc: mvsdio: use devm_ API to simplify/correct error paths.
clk: mvebu/clk-cpu.c: fix memory leakage
Pull more USB fixes from Greg Kroah-Hartman:
"Here are some more USB fixes for the 3.8-rc4 tree.
Some gadget driver fixes, and finally resolved the ehci-mxc driver
build issues (it's just some code moving around and being deleted)."
* tag 'usb-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: EHCI: fix build error in ehci-mxc
USB: EHCI: add a name for the platform-private field
USB: EHCI: fix incorrect configuration test
USB: EHCI: Move definition of EHCI_STATS to ehci.h
USB: UHCI: fix IRQ race during initialization
usb: gadget: FunctionFS: Fix missing braces in parse_opts
usb: dwc3: gadget: fix ep->maxburst for ep0
ARM: i.MX clock: Change the connection-id for fsl-usb2-udc
usb: gadget: fsl_mxc_udc: replace MX35_IO_ADDRESS to ioremap
usb: gadget: fsl-mxc-udc: replace cpu_is_xxx() with platform_device_id
usb: musb: cppi_dma: drop '__init' annotation
Pull drivers/misc fix from Greg Kroah-Hartman:
"Here is a single revert for the ti-st misc driver, fixing problem that
was introduced in 3.7-rc1 that has been bothering people."
* tag 'char-misc-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
Revert "drivers/misc/ti-st: remove gpio handling"
Pull media fixes from Mauro Carvalho Chehab:
- gspca: add needed delay for I2C traffic for sonixb/sonixj cameras
- gspca: add one missing Kinect USB ID
- usbvideo: some regression fixes
- omap3isp: fix some build issues
- videobuf2: fix video output handling
- exynos s5p/m5mols: a few regression fixes.
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
[media] uvcvideo: Set error_idx properly for S_EXT_CTRLS failures
[media] uvcvideo: Cleanup leftovers of partial revert
[media] uvcvideo: Return -EACCES when trying to set a read-only control
[media] omap3isp: Don't include <plat/cpu.h>
[media] s5p-mfc: Fix interrupt error handling routine
[media] s5p-fimc: Fix return value of __fimc_md_create_flite_source_links()
[media] m5mols: Fix typo in get_fmt callback
[media] v4l: vb2: Set data_offset to 0 for single-plane output buffers
[media] [FOR,v3.8] omap3isp: Don't include deleted OMAP plat/ header files
[media] gspca_sonixj: Add a small delay after i2c_w1
[media] gspca_sonixb: Properly wait between i2c writes
[media] gspca_kinect: add Kinect for Windows USB id
This patch (as1643b) fixes a build error in ehci-hcd when compiling for
ARM with allmodconfig:
drivers/usb/host/ehci-hcd.c:1285:0: warning: "PLATFORM_DRIVER" redefined [enabled by default]
drivers/usb/host/ehci-hcd.c:1255:0: note: this is the location of the previous definition
drivers/usb/host/ehci-mxc.c:280:31: warning: 'ehci_mxc_driver' defined but not used [-Wunused-variable]
drivers/usb/host/ehci-hcd.c:1285:0: warning: "PLATFORM_DRIVER" redefined [enabled by default]
drivers/usb/host/ehci-hcd.c:1255:0: note: this is the location of the previous definition
The fix is to convert ehci-mxc over to the new "ehci-hcd is a library"
scheme so that it can coexist peacefully with the ehci-platform
driver. As part of the conversion the ehci_mxc_priv data structure,
which was allocated dynamically, is now placed where it belongs: in
the private area at the end of struct ehci_hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit eccf2979b2.
The reason is that it broke TI WiLink shared transport on Panda.
Also, callback functions should not be added to board files anymore,
so revert to implementing the power functions in the driver itself.
Additionally, changed a variable name ('status' to 'err') so that this
revert compiles properly.
Cc: stable <stable@vger.kernel.org> [3.7]
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a number of bugs in the error paths of this driver. Make
use of devm_ functions to simplify the cleanup on error.
Based on a patch by Russell King.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Pull PCI updates from Bjorn Helgaas:
"The most important is a fix for a pciehp deadlock that occurs when
unplugging a Thunderbolt adapter. We also applied the same fix to
shpchp, removed CONFIG_EXPERIMENTAL dependencies, fixed a
pcie_aspm=force problem, and fixed a refcount leak.
Details:
- Hotplug
PCI: pciehp: Use per-slot workqueues to avoid deadlock
PCI: shpchp: Make shpchp_wq non-ordered
PCI: shpchp: Handle push button event asynchronously
PCI: shpchp: Use per-slot workqueues to avoid deadlock
- Power management
PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported
- Misc
PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()
PCI: remove depends on CONFIG_EXPERIMENTAL"
* tag '3.8-pci-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: remove depends on CONFIG_EXPERIMENTAL
PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported
PCI: shpchp: Use per-slot workqueues to avoid deadlock
PCI: shpchp: Handle push button event asynchronously
PCI: shpchp: Make shpchp_wq non-ordered
PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()
PCI: pciehp: Use per-slot workqueues to avoid deadlock
The acpi core will call request_module("acpi-cpufreq") on subsystem init,
but this will fail if the module isn't available at that stage of boot.
Add some module aliases to ensure that udev can load the module on Intel
and AMD systems with the appropriate feature bits - I /think/ that this
will also work on VIA systems, but haven't verified that.
References: http://lkml.kernel.org/r/1448223.sdUJnNSRz4@vostro.rjw.lan
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Tested-by: Leonid Isaev <lisaev@umail.iu.edu>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: 3.7+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull GPIO fixes from Linus Walleij:
"Here are some GPIO fixes I stacked up in my GPIO tree:
- Remove a bad #include from the Samsung driver
- Some Kconfig hazzle for the Samsungs
- Skip gpiolib registration on EXYNOS5440
- Don't free the MVEBU label"
* tag 'fixes-for-v3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio: mvebu: Don't free chip label memory
gpio: samsung: skip gpio lib registration for EXYNOS5440
gpio: samsung: silent build warning for EXYNOS5 SoCs
gpio: samsung: fix pinctrl condition for exynos and exynos5440
gpio: samsung: remove inclusion <mach/regs-clock.h>
From Tony Lindgren:
Minimal omap fixes for the -rc series:
- A build fix for recently merged omap DRM changes
- Regression fixes from the common clock framework conversion
for omap4 audio and omap2 reboot
- Regression fix for pandaboard WLAN control UART muxing caused by
u-boot only muxing essential pins nowadays
- Timer iteration fix for CONFIG_OF_DYNAMIC
- A section mismatch fix for ocp2scp init
* tag 'omap-for-v3.8-rc4/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (306 commits)
ARM: OMAP2+: omap4-panda: add UART2 muxing for WiLink shared transport
ARM: OMAP2+: DT node Timer iteration fix
ARM: OMAP2+: Fix section warning for omap_init_ocp2scp()
ARM: OMAP2+: fix build break for omapdrm
ARM: OMAP2: Fix missing omap2xxx_clkt_vps_late_init function calls
ARM: OMAP4: hwmod_data: Correct IDLEMODE for McPDM
ARM: OMAP4: clock data: Lock ABE DPLL on all revisions
+ Linux 3.8-rc4
Signed-off-by: Olof Johansson <olof@lixom.net>
Pull vfio fix from Alex Williamson.
"vfio-pci: Fix buffer overfill"
* tag 'vfio-for-v3.8-rc5' of git://github.com/awilliam/linux-vfio:
vfio-pci: Fix buffer overfill
Pull libata fixes from Jeff Garzik:
1) ahci: Fix typo that caused erronenous error handling.
Thought: I wonder if sparse could have caught this, somehow.
2) ahci: support a slightly odd Enmotus variant
3) core: fix a drive detection problem by correcting the logic by which
the DevSlp timing variables are obtained and used.
* tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[libata] replace sata_settings with devslp_timing
[libata] ahci: Add support for Enmotus Bobcat device.
[libata] ahci: Fix lack of command retry after a success error handler.
This patch (as1642) adds an ehci->priv field for private use by EHCI
platform drivers. The space was provided some time ago, but it didn't
have a name.
Until now none of the platform drivers has used this private space,
but that's about to change in the next patch of this series.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1641) fixes a minor bug in ehci-hcd left over from when
the Chipidea driver was converted to the "ehci-hcd is a library"
scheme. The test for whether the Chipidea platform driver is active
should be IS_ENABLED(), not defined().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without this, platform drivers e.g. ehci-omap.c will see a
different version of struct ehci_hcd than ehci-hcd.c and
break reference to 'debug_dir' and 'priv' members when
CONFIG_USB_DEBUG is enabled.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1644) fixes a race that occurs during startup in
uhci-hcd. If the IRQ line is shared with other devices, it's possible
for the handler routine to be called before the data structures are
fully initialized.
The problem is fixed by adding a check to the IRQ handler routine. If
the initialization hasn't finished yet, the routine will return
immediately.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Don Zickus <dzickus@redhat.com>
Tested-by: "Huang, Adrian (ISS Linux TW)" <adrian.huang@hp.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver can also be built as a module so add MODULE_LICENSE for it. In
addition add MODULE_DESCRIPTION as well.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Commit 0bdfe0cb80 (i2c: omap: sanitize
exit path) changed the interrupt handler to exit early and complete
the transfer after the draining IRQ is handled. As a result, the ARDY
may not be cleared properly, and it may cause all future I2C transfers
to timeout with "timeout waiting for bus ready". This is reproducible
at least with N900 when twl4030_gpio makes a long write (> FIFO size)
during the probe (http://marc.info/?l=linux-omap&m=135818882610432&w=2).
The fix is to continue until we get ARDY interrupt that completes the
transfer. Tested with 3.8-rc4 + N900: 20 boots in a row without errors;
without the patch the problem triggers after few reboots.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
The errata handling function acks wrong interrupt in case of "Arbitration
lost". Fix it.
Discovered during code review, the real impact of the bug is unknown.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
To fix incorrect P-state frequencies which can happen on
some AMD systems f594065faf
"ACPI: Add fixups for AMD P-state figures"
introduced a quirk to obtain the correct values by reading
from AMD specific MSRs.
This did cause a regression when running a kernel using that
quirk under Xen which does (currently) not pass through MSR
reads to the HW. Instead the guest gets a 0 in return.
And this seems to cause a failure to initialize the ondemand
governour (hard to say for sure as all P-states appear to run
at the same frequency).
While this should also be fixed in the hypervisor (to allow
a guest to read that MSR), this patch is intended to work
around the issue in the meantime. In discussion it turned out
that indeed real HW/BIOSes may choose to not set the valid bit
and thus mark the P-state as invalid. So this could be considered
a fix for broken BIOSes that also works around the issue on Xen.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Cc: 3.7+ <stable@vger.kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
OPP pointers cannot be expected to be valid beyond the boundary
of rcu_read_lock and rcu_read_unlock. Unfortunately, the current
exynos4 busfreq driver does not honor the usage constraint and stores
the OPP pointer in struct busfreq_data. This could potentially
become invalid later such as: across devfreq opp change decisions,
resulting in unpredictable behavior.
To fix this, we introduce a busfreq specific busfreq_opp_info
structure which is used to handle OPP information. OPP information
is de-referenced to voltage and frequency pairs as needed into
busfreq_opp_info structure and used as needed.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
OPP pointers are protected by RCU locks, the pointer validity is
permissible only under the section of rcu_read_lock to rcu_read_unlock
Add documentation to the effect.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
OPP pointer is RCU protected, hence after finding it, de-reference
also should be protected with the same RCU context else the OPP
pointer may become invalid.
Reported-by: Jack Mitchell <jack@embed.me.uk>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Tested-by: Jack Mitchell <jack@embed.me.uk>
Acked-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
