Re: [PATCH] gpio: pca953x: Handle direction register read errors in IRQ paths

[Bartosz Golaszewski]

On Sun, 18 Oct 2026 18:50:03 +0200, Sahaj Chaudhari
<sahaj123.sc@xxxxxxxxx> said:
> Three IRQ paths ignore the result of reading the direction registers
> and then use the destination bitmap. pca953x_read_regs() does not populate
> that bitmap when regmap_bulk_read() fails, leaving the callers to use
> uninitialized stack data.
>
> This can select incorrect GPIOs for direction changes during IRQ bus
> synchronization, corrupt the saved input state during IRQ setup, or
> produce incorrect pending interrupt decisions.
>
> Check the read result at all three sites. Release irq_lock without
> changing GPIO directions on failure, leave the IRQ history untouched
> when pending detection fails, and propagate the error from IRQ setup.
> The read helper already logs the error.
>
> Fixes: 0f25fda840a9 ("gpio: pca953x: Zap ad-hoc reg_direction cache")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sahaj Chaudhari <sahaj123.sc@xxxxxxxxx>
> ---

Sashiko is technically right but we're staying in the same scope with the jump
and we can't guard the irq lock in this specific case so I'll ignore it.

Bart