Re: [PATCH] Input: adp5588-keys - cache GPIO state before registering the gpiochip
Dmitry Torokhov <[email protected]>
| Newsgroups | org.kernel.vger.linux-gpio,org.kernel.vger.linux-input,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Tue, Aug 18, 2026 at 06:00:02PM +0200, Alvin Šipraga wrote:
> So as not to clobber any pre-programmed GPIO state in the execution
> of its gpiochip ops, the driver caches things during probe time.
> However, since those ops can be called both during and immediately after
> the call to devm_gpiochip_add_data(), it is imperative that things are
> cached before that. That's not the case right now, so reorder the two
> steps to prevent any clobbering.
>
> In a conrete example which motivated this change, a bootloader was
> preconfiguring an important GPIO output to HIGH before booting the
> kernel. Linux would then inadvertently set that output to LOW while
> configuring a GPIO hog on a discrete GPIO line within the same 8-bit
> bank (because the cached value was 0=LOW).
>
> Fixes: ba9f507a1bea ("Input: adp5588-keys - export unused GPIO pins")
> Signed-off-by: Alvin Šipraga <[email protected]>
Applied, thank you.
--
Dmitry