Re: [PATCH] arm64: dts: qcom: add debug UART pins to reserved GPIO ranges on RB2

[Bartosz Golaszewski]

On Mon, Jun 16, 2025 at 6:20 PM Konrad Dybcio
<konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>
> On 6/16/25 4:33 PM, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > GPIO12 and GPIO13 are used for the debug UART and must not be available
> > to drivers or user-space. Add them to the gpio-reserved-ranges.
> >
> > Fixes: 8d58a8c0d930c ("arm64: dts: qcom: Add base qrb4210-rb2 board dts")
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > ---
>
> That also makes them unavailable to the kernel though, no?
>

Yes. They could only be used by QUP - I2C or SPI #4 - on sm6115 but
none of these are used on RB2. I just noticed that my console froze
when I accidentally requested GPIO12 and figured that it makes sense
to make them unavailable. Let me know if this should be dropped.

Bart