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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAMRc=MceV-HgyFFvqytXAiuY+y10PQbdPBxuvd57NCeSLVLXCg@mail.gmail.com>
Date: Mon, 16 Jun 2025 18:43:16 +0200
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: Bjorn Andersson <andersson@...nel.org>, Konrad Dybcio <konradybcio@...nel.org>, 
	Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH] arm64: dts: qcom: add debug UART pins to reserved GPIO
 ranges on RB2

On Mon, Jun 16, 2025 at 6:20 PM Konrad Dybcio
<konrad.dybcio@....qualcomm.com> wrote:
>
> On 6/16/25 4:33 PM, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> >
> > 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@...aro.org>
> > ---
>
> 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