Re: [PATCH RESEND] Do not mark ACPI devices as irq safe

[Andi Shyti]

Hi,

On Thu, Aug 08, 2024 at 05:14:46AM GMT, Breno Leitao wrote:
> On ACPI machines, the tegra i2c module encounters an issue due to a
> mutex being called inside a spinlock. This leads to the following bug:
> 
> 	BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
> 	in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1282, name: kssif0010
> 	preempt_count: 0, expected: 0
> 	RCU nest depth: 0, expected: 0
> 	irq event stamp: 0
> 
> 	Call trace:
> 	dump_backtrace+0xf0/0x140
> 	show_stack (./arch/x86/include/asm/current.h:49
> 		     arch/x86/kernel/dumpstack.c:312)
> 	dump_stack_lvl (lib/dump_stack.c:89 lib/dump_stack.c:115)
> 	dump_stack (lib/earlycpio.c:61)
> 	__might_resched (./arch/x86/include/asm/current.h:49
> 			 kernel/sched/core.c:10297)
> 	__might_sleep (./include/linux/lockdep.h:231
> 			 kernel/sched/core.c:10236)
> 	__mutex_lock_common+0x5c/0x2190
> 	mutex_lock_nested (kernel/locking/mutex.c:751)
> 	acpi_subsys_runtime_resume+0xb8/0x160
> 	__rpm_callback+0x1cc/0x4b0
> 	rpm_resume+0xa60/0x1078
> 	__pm_runtime_resume+0xbc/0x130
> 	tegra_i2c_xfer+0x74/0x398
> 	__i2c_transfer (./include/trace/events/i2c.h:122 drivers/i2c/i2c-core-base.c:2258)
> 
> The problem arises because during __pm_runtime_resume(), the spinlock
> &dev->power.lock is acquired before rpm_resume() is called. Later,
> rpm_resume() invokes acpi_subsys_runtime_resume(), which relies on
> mutexes, triggering the error.
> 
> To address this issue, devices on ACPI are now marked as not IRQ-safe,
> considering the dependency of acpi_subsys_runtime_resume() on mutexes.
> 
> Co-developed-by: Michael van der Westhuizen <rmikey@xxxxxxxx>
> Signed-off-by: Michael van der Westhuizen <rmikey@xxxxxxxx>
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 85b31edc558d..6d783ecc3431 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -1804,7 +1804,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
>  	 * VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
>  	 * be used for atomic transfers.
>  	 */
> -	if (!IS_VI(i2c_dev))
> +	if (!IS_VI(i2c_dev) && !ACPI_HANDLE(i2c_dev->dev))

looks good to me, can I have an ack from Andy here?

Thanks,
Andi

>  		pm_runtime_irq_safe(i2c_dev->dev);
>  
>  	pm_runtime_enable(i2c_dev->dev);
> -- 
> 2.43.5
>