* drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq
@ 2024-07-01 16:30 Dan Carpenter
2024-07-01 17:14 ` Dmitry Torokhov
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2024-07-01 16:30 UTC (permalink / raw)
To: oe-kbuild, Ronald Tschalär
Cc: lkp, oe-kbuild-all, linux-kernel, Dmitry Torokhov, Andy Shevchenko
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 6d6444ba82053c716fb5ac83346202659023044e
commit: 038b1a05eae6666b731920e46f47d8e2332e07ff Input: add Apple SPI keyboard and trackpad driver
config: x86_64-randconfig-161-20240628 (https://download.01.org/0day-ci/archive/20240628/202406280337.1Av9qm8V-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202406280337.1Av9qm8V-lkp@intel.com/
smatch warnings:
drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq
drivers/input/keyboard/applespi.c:1845 applespi_drain_reads() warn: mixing irqsave and irq
vim +1833 drivers/input/keyboard/applespi.c
038b1a05eae666 Ronald Tschalär 2019-07-15 1826 static void applespi_drain_writes(struct applespi_data *applespi)
038b1a05eae666 Ronald Tschalär 2019-07-15 1827 {
038b1a05eae666 Ronald Tschalär 2019-07-15 1828 unsigned long flags;
038b1a05eae666 Ronald Tschalär 2019-07-15 1829
038b1a05eae666 Ronald Tschalär 2019-07-15 1830 spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
_irqsave() sort of implies that potentially the caller has disabled IRQs,
otherwise we would use spin_lock_irq() if we knew they hadn't disabled
IRQs.
038b1a05eae666 Ronald Tschalär 2019-07-15 1831
038b1a05eae666 Ronald Tschalär 2019-07-15 1832 applespi->drain = true;
038b1a05eae666 Ronald Tschalär 2019-07-15 @1833 wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
038b1a05eae666 Ronald Tschalär 2019-07-15 1834 applespi->cmd_msg_lock);
This will renable IRQs briefly and then disable them again.
038b1a05eae666 Ronald Tschalär 2019-07-15 1835
038b1a05eae666 Ronald Tschalär 2019-07-15 1836 spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
This will set them back to how they were at the start of the function.
The issue is that if the caller really wanted IRQs disabled, then it's
not necessarilly a good idea to enable them at all in the
wait_event_lock_irq() macro. I suspect that in real life no callers
disable IRQs so it's not an issue. But anyway, that's what the warning
is about.
I suspect that kbuild-bot has a 5 year cut off for warnings and if this
had been a month older then kbuild-bot would have ignored it. :P
038b1a05eae666 Ronald Tschalär 2019-07-15 1837 }
038b1a05eae666 Ronald Tschalär 2019-07-15 1838
038b1a05eae666 Ronald Tschalär 2019-07-15 1839 static void applespi_drain_reads(struct applespi_data *applespi)
038b1a05eae666 Ronald Tschalär 2019-07-15 1840 {
038b1a05eae666 Ronald Tschalär 2019-07-15 1841 unsigned long flags;
038b1a05eae666 Ronald Tschalär 2019-07-15 1842
038b1a05eae666 Ronald Tschalär 2019-07-15 1843 spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
038b1a05eae666 Ronald Tschalär 2019-07-15 1844
038b1a05eae666 Ronald Tschalär 2019-07-15 @1845 wait_event_lock_irq(applespi->drain_complete, !applespi->read_active,
038b1a05eae666 Ronald Tschalär 2019-07-15 1846 applespi->cmd_msg_lock);
038b1a05eae666 Ronald Tschalär 2019-07-15 1847
038b1a05eae666 Ronald Tschalär 2019-07-15 1848 applespi->suspended = true;
038b1a05eae666 Ronald Tschalär 2019-07-15 1849
038b1a05eae666 Ronald Tschalär 2019-07-15 1850 spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
038b1a05eae666 Ronald Tschalär 2019-07-15 1851 }
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq
2024-07-01 16:30 drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq Dan Carpenter
@ 2024-07-01 17:14 ` Dmitry Torokhov
2024-07-01 17:21 ` Dan Carpenter
0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Torokhov @ 2024-07-01 17:14 UTC (permalink / raw)
To: Dan Carpenter
Cc: oe-kbuild, Ronald Tschalär, lkp, oe-kbuild-all,
linux-kernel, Andy Shevchenko
Hi Dan,
On Mon, Jul 01, 2024 at 06:30:38PM +0200, Dan Carpenter wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 6d6444ba82053c716fb5ac83346202659023044e
> commit: 038b1a05eae6666b731920e46f47d8e2332e07ff Input: add Apple SPI keyboard and trackpad driver
> config: x86_64-randconfig-161-20240628 (https://download.01.org/0day-ci/archive/20240628/202406280337.1Av9qm8V-lkp@intel.com/config)
> compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202406280337.1Av9qm8V-lkp@intel.com/
>
> smatch warnings:
> drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq
> drivers/input/keyboard/applespi.c:1845 applespi_drain_reads() warn: mixing irqsave and irq
>
> vim +1833 drivers/input/keyboard/applespi.c
>
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1826 static void applespi_drain_writes(struct applespi_data *applespi)
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1827 {
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1828 unsigned long flags;
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1829
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1830 spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
>
> _irqsave() sort of implies that potentially the caller has disabled IRQs,
> otherwise we would use spin_lock_irq() if we knew they hadn't disabled
> IRQs.
>
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1831
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1832 applespi->drain = true;
> 038b1a05eae666 Ronald Tschalär 2019-07-15 @1833 wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1834 applespi->cmd_msg_lock);
>
> This will renable IRQs briefly and then disable them again.
>
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1835
> 038b1a05eae666 Ronald Tschalär 2019-07-15 1836 spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
>
> This will set them back to how they were at the start of the function.
>
> The issue is that if the caller really wanted IRQs disabled, then it's
> not necessarilly a good idea to enable them at all in the
> wait_event_lock_irq() macro. I suspect that in real life no callers
> disable IRQs so it's not an issue. But anyway, that's what the warning
> is about.
applespi_drain_writes() and applespi_drain_reads() are only called from
the process context with interrupts enabled, so it looks like we should
simply change spin_lock_irqsave() to spin_lock_irq().
I am taking patches ;)
Thanks.
--
Dmitry
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq
2024-07-01 17:14 ` Dmitry Torokhov
@ 2024-07-01 17:21 ` Dan Carpenter
0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2024-07-01 17:21 UTC (permalink / raw)
To: Dmitry Torokhov
Cc: oe-kbuild, Ronald Tschalär, lkp, oe-kbuild-all,
linux-kernel, Andy Shevchenko
On Mon, Jul 01, 2024 at 10:14:00AM -0700, Dmitry Torokhov wrote:
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1826 static void applespi_drain_writes(struct applespi_data *applespi)
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1827 {
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1828 unsigned long flags;
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1829
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1830 spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> >
> > _irqsave() sort of implies that potentially the caller has disabled IRQs,
> > otherwise we would use spin_lock_irq() if we knew they hadn't disabled
> > IRQs.
> >
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1831
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1832 applespi->drain = true;
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 @1833 wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1834 applespi->cmd_msg_lock);
> >
> > This will renable IRQs briefly and then disable them again.
> >
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1835
> > 038b1a05eae666 Ronald Tschalär 2019-07-15 1836 spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> >
> > This will set them back to how they were at the start of the function.
> >
> > The issue is that if the caller really wanted IRQs disabled, then it's
> > not necessarilly a good idea to enable them at all in the
> > wait_event_lock_irq() macro. I suspect that in real life no callers
> > disable IRQs so it's not an issue. But anyway, that's what the warning
> > is about.
>
> applespi_drain_writes() and applespi_drain_reads() are only called from
> the process context with interrupts enabled, so it looks like we should
> simply change spin_lock_irqsave() to spin_lock_irq().
>
> I am taking patches ;)
Sure. I can send that.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-07-01 16:30 drivers/input/keyboard/applespi.c:1833 applespi_drain_writes() warn: mixing irqsave and irq Dan Carpenter
2024-07-01 17:14 ` Dmitry Torokhov
2024-07-01 17:21 ` Dan Carpenter
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