Due to broken iowait task counting design (cf: comments above
get_cpu_idle_time_us() and nr_iowait()), it is not possible to provide
the guarantee that /proc/stat or /proc/uptime display monotonic idle
time values.
Remove the assertions that verify the related wrong assumption so that
testers and maintainers don't spend more time on that.
Reported-by: Yu Liao <liaoyu15@huawei.com>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230222144649.624380-8-frederic@kernel.org
The per-cpu iowait task counter is incremented locally upon sleeping.
But since the task can be woken to (and by) another CPU, the counter may
then be decremented remotely. This is the source of a race involving
readers VS writer of idle/iowait sleeptime.
The following scenario shows an example where a /proc/stat reader
observes a pending sleep time as IO whereas that pending sleep time
later eventually gets accounted as non-IO.
CPU 0 CPU 1 CPU 2
----- ----- ------
//io_schedule() TASK A
current->in_iowait = 1
rq(0)->nr_iowait++
//switch to idle
// READ /proc/stat
// See nr_iowait_cpu(0) == 1
return ts->iowait_sleeptime +
ktime_sub(ktime_get(), ts->idle_entrytime)
//try_to_wake_up(TASK A)
rq(0)->nr_iowait--
//idle exit
// See nr_iowait_cpu(0) == 0
ts->idle_sleeptime += ktime_sub(ktime_get(), ts->idle_entrytime)
As a result subsequent reads on /proc/stat may expose backward progress.
This is unfortunately hardly fixable. Just add a comment about that
condition.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-5-frederic@kernel.org
Reading idle/IO sleep time (eg: from /proc/stat) can race with idle exit
updates because the state machine handling the stats is not atomic and
requires a coherent read batch.
As a result reading the sleep time may report irrelevant or backward
values.
Fix this with protecting the simple state machine within a seqcount.
This is expected to be cheap enough not to add measurable performance
impact on the idle path.
Note this only fixes reader VS writer condition partitially. A race
remains that involves remote updates of the CPU iowait task counter. It
can hardly be fixed.
Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-4-frederic@kernel.org
The idle and IO sleeptime statistics appearing in /proc/stat can be
currently updated from two sites: locally on idle exit and remotely
by cpufreq. However there is no synchronization mechanism protecting
concurrent updates. It is therefore possible to account the sleeptime
twice, among all the other possible broken scenarios.
To prevent from breaking the sleeptime accounting source, restrict the
sleeptime updates to the local idle exit site. If there is a delta to
add since the last update, IO/Idle sleep time readers will now only
compute the delta without actually writing it back to the internal idle
statistic fields.
This fixes a writer VS writer race. Note there are still two known
reader VS writer races to handle. A subsequent patch will fix one.
Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-3-frederic@kernel.org
Currently SPI Cadence controller works only in Master mode.
Updated interrupt handler for Full duplex transfer in Slave mode.
Interrupt handler rely on the TX empty interrupt even for Slave mode
transfer due to below HW limitation.
HW limitation:
AR 65885 - SPI Controller Might Not Update RX_NEMPTY Flag, Showing
Incorrect Status Of The Receive FIFO
SPI Slave mode works in the following manner:
1. One transfer can be finished only after all transfer->len
data been transferred to master device.
2. Slave device only accepts transfer->len data. Any data longer
than this from master device will be dropped. Any data shorter than
this from master will cause SPI to be stuck due to the above behavior.
3. The stale data present in RXFIFO will be dropped in unprepared
hardware transfer function.
Signed-off-by: Srinivas Goud <srinivas.goud@amd.com>
Link: https://lore.kernel.org/r/1681825625-10265-3-git-send-email-srinivas.goud@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
On the Rock5b a fix the newly added rtc node and cpu-regulators for the big
cluster. Volume-keys (via adc) for the Pinephone Pro, display support for
the Anbernic RG353. As well as gpio-ranges for rk356x and fixes for the
audio-codec node-names on two boards.
* tag 'v6.4-rockchip-dts64-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
arm64: dts: rockchip: Add support for volume keys to rk3399-pinephone-pro
arm64: dts: rockchip: Add vdd_cpu_big regulators to rk3588-rock-5b
arm64: dts: rockchip: Use generic name for es8316 on Pinebook Pro and Rock 5B
arm64: dts: rockchip: Drop RTC clock-frequency on rk3588-rock-5b
arm64: dts: rockchip: Add pinctrl gpio-ranges for rk356x
arm64: dts: rockchip: add panel to Anbernic RG353 series
Link: https://lore.kernel.org/r/5144826.MHq7AAxBmi@phil
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Commit 75a2d4226b ("driver core: class: mark the struct class for
sysfs callbacks as constant") changed the attribute to use
CLASS_ATTR_RO() which changed the permission from 0400 to 0444. But
this atribute is "special" in that reading it modifies the system state,
so it MUST be set to 0400 so that only root processes can muck around
with it.
Fix this all up, AND document this so that I don't change it again in
3-4 years when I stumble across it and wonder why it's an open-coded
_ATTR() macro.
Reported-by: Denis Efremov <efremov@linux.com>
Fixes: 75a2d4226b ("driver core: class: mark the struct class for sysfs callbacks as constant")
Link: https://lore.kernel.org/r/2023041810-angelic-conical-52d8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull OPP updates for 6.4 from Viresh Kumar:
"- Use of_property_present() for testing DT property presence (Rob
Herring).
- Add set_required_opps() callback to the 'struct opp_table', to make
the code paths cleaner (Viresh Kumar)."
* tag 'opp-updates-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
OPP: Move required opps configuration to specialized callback
OPP: Handle all genpd cases together in _set_required_opps()
opp: Use of_property_present() for testing DT property presence
Add support for DLVR (Digital Linear Voltage Regulator) attributes,
which can be used to control RFIM.
Here instead of "fivr" another directory "dlvr" is created with DLVR
attributes:
/sys/bus/pci/devices/0000:00:04.0/dlvr
├── dlvr_freq_mhz
├── dlvr_freq_select
├── dlvr_hardware_rev
├── dlvr_pll_busy
├── dlvr_rfim_enable
└── dlvr_spread_spectrum_pct
└── dlvr_control_mode
└── dlvr_control_lock
Attributes
dlvr_freq_mhz (RO):
Current DLVR PLL frequency in MHz.
dlvr_freq_select (RW):
Sets DLVR PLL clock frequency.
dlvr_hardware_rev (RO):
DLVR hardware revision.
dlvr_pll_busy (RO):
PLL can't accept frequency change when set.
dlvr_rfim_enable (RW):
0: Disable RF frequency hopping, 1: Enable RF frequency hopping.
dlvr_control_mode (RW):
Specifies how frequencies are spread. 0: Down spread, 1: Spread in Center.
dlvr_control_lock (RW):
1: future writes are ignored.
dlvr_spread_spectrum_pct (RW)
A write to this register updates the DLVR spread spectrum percent value.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With HIGHRES enabled tick_sched_timer() is programmed every jiffy to
expire the timer_list timers. This timer is programmed accurate in
respect to CLOCK_MONOTONIC so that 0 seconds and nanoseconds is the
first tick and the next one is 1000/CONFIG_HZ ms later. For HZ=250 it is
every 4 ms and so based on the current time the next tick can be
computed.
This accuracy broke since the commit mentioned below because the jiffy
based clocksource is initialized with higher accuracy in
read_persistent_wall_and_boot_offset(). This higher accuracy is
inherited during the setup in tick_setup_device(). The timer still fires
every 4ms with HZ=250 but timer is no longer aligned with
CLOCK_MONOTONIC with 0 as it origin but has an offset in the us/ns part
of the timestamp. The offset differs with every boot and makes it
impossible for user land to align with the tick.
Align the tick period with CLOCK_MONOTONIC ensuring that it is always a
multiple of 1000/CONFIG_HZ ms.
Fixes: 857baa87b6 ("sched/clock: Enable sched clock early")
Reported-by: Gusenleitner Klaus <gus@keba.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20230406095735.0_14edn3@linutronix.de
Link: https://lore.kernel.org/r/20230418122639.ikgfvu3f@linutronix.de
The cadence QSPI driver misbehaves after performing a full system suspend
resume:
...
spi-nor spi0.0: resume() failed
...
This results in a flash connected via OSPI interface after system suspend-
resume to be unusable.
fix these suspend and resume functions.
Fixes: 1406234105 ("mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller")
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230417091027.966146-3-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
clang build reports
sound/soc/codecs/nau8825.c:2826:31: error: overlapping comparisons
always evaluate to false [-Werror,-Wtautological-overlap-compare]
if (nau8825->adc_delay < 125 && nau8825->adc_delay > 500)
~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
This is a bug, a logical-or should have been used.
Fixes: fc0b096c92 ("ASoC: nau8825: Add delay control for input path")
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: David Lin <CTLIN0@nuvoton.com>
Link: https://lore.kernel.org/r/20230418120955.3230705-1-trix@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Since commit 27a2660f1e ("gfs2: Dump nrpages for inodes and their
glocks"), inode_go_dump() computes the address of inode within ip before
checking if ip is NULL. This isn't a bug by itself, but it can give
rise to bugs later. Avoid that by checking if ip is NULL first.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When we first add the STA before sending an authentication
frame this is false. However, in some cases such as FT or
certainly in MLO link switch scenarios, it will be true.
If it happens to be true, it causes a firmware assert (in
LMAC, 0x2528), because the same bit is used by the firmware
for tracking this setting as well as for tracking if the
management key has been installed, and then we get this
assert from the firmware when installing the MFP key as it
thinks it has already been installed.
Remove the setting for now, until the firmware disentangles
the two. We should be able to set it, in fact we should be
setting it speculatively before authentication/association,
to avoid processing management frames that should have been
protected/encrypted before the key is set.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230417113648.adbeb0e0bfed.I400d0ee3721dc4f294313be992d277ba4d9c88d9@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Before this patch function init_journal() used a local variable jindex to
keep track of whether it needed to dequeue the jindex holder when errors
were found. It also uselessly set the variable just before returning from
the function. This patch simplifies the code by eliminatinng the local
variable in favor of using function gfs2_holder_initialized.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Function gfs2_trim_blocks is not referenced. Eliminate it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
These got*, plt* and .text.ftrace_trampoline sections specified for
LoongArch have non-zero addressses. Non-zero section addresses in a
relocatable ELF would confuse GDB when it tries to compute the section
offsets and it ends up printing wrong symbol addresses. Therefore, set
them to zero, which mirrors the change in commit 5d8591bc0f
("arm64 module: set plt* section addresses to 0x0").
Cc: stable@vger.kernel.org
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Chong Qiao <qiaochong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
vm_map_base, empty_zero_page and invalid_pmd_table could be accessed
widely by some out-of-tree non-GPL but important file systems or drivers
(e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL()
to export them, so as to avoid build errors.
1, Details about vm_map_base:
This is a LoongArch-specific symbol and may be referenced through macros
PCI_IOBASE, VMALLOC_START and VMALLOC_END.
2, Details about empty_zero_page:
As it stands today, only 3 architectures export empty_zero_page as a GPL
symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by
inheriting from MIPS, and the MIPS export was first introduced in commit
497d2adcbf ("[MIPS] Export empty_zero_page for sake of the ext4
module."). The IA64 export was similar: commit a7d57ecf42 ("[IA64]
Export three symbols for module use") did so for kvm.
In both IA64 and MIPS, the export of empty_zero_page was done for
satisfying some in-kernel component built as module (kvm and ext4
respectively), and given its reasonably low-level nature, GPL is a
reasonable choice. But looking at the bigger picture it is evident most
other architectures do not regard it as GPL, so in effect the symbol
probably should not be treated as such, in favor of consistency.
3, Details about invalid_pmd_table:
Keep consistency with invalid_pte_table and make it be possible by some
modules.
Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Some firmwares don't enable PG when wakeup from suspend, so do it in
kernel. This can improve code compatibility for boot kernel.
Signed-off-by: Baoqi Zhang <zhangbaoqi@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
