Subject: Re: [PATCH 2/7] i2c: core: Use generic_handle_irq_safe() in i2c_handle_smbus_host_notify().

From: Wolfram Sang <[email-masked]>
Date: Thu, 27 Jan 2022 18:11:16 +0100

On Thu, Jan 27, 2022 at 12:32:58PM +0100, Sebastian Andrzej Siewior wrote:
> The i2c-i801 driver invokes i2c_handle_smbus_host_notify() from his
> interrupt service routine. On PREEMPT_RT i2c-i801's handler is forced
> threaded with enabled interrupts which leads to a warning by
> handle_irq_event_percpu() assuming that irq_default_primary_handler()
> enabled interrupts.
> 
> i2c-i801's interrupt handler can't be made non-threaded because the
> interrupt line is shared with other devices.
> 
> Use generic_handle_irq_safe() which can invoked with disabled and enabled
> interrupts.
> 
> Reported-by: Michael Below <[email-masked]>
> Link: https://bugs.debian.org/1002537
> Cc: Salvatore Bonaccorso <[email-masked]>
> Signed-off-by: Sebastian Andrzej Siewior <[email-masked]>

I guess you want this to go together with patch 1, so:

Acked-by: Wolfram Sang <[email-masked]>

I agree with adding the kernel bugzilla entry at least:

https://bugzilla.kernel.org/show_bug.cgi?id=202453

Probably the others which Oleksandr metioned, too.