Re: [PATCH v2 0/2] Add psci_sys_reset2 reboot modes for Qualcomm boards

[Shivendra Pratap]

On 12-06-2026 13:51, Lorenzo Pieralisi wrote:
> On Wed, Jun 10, 2026 at 02:57:19PM +0200, Loic Poulain wrote:
> > Hi Anurag,
> >
> > On Fri, May 29, 2026 at 4:29 PM Anurag Pateriya
> > <anurag.pateriya@xxxxxxxxxxxxxxxx> wrote:
> > > Adding PSCI SYSTEM_RESET2 reboot-modes for sm8750 and
> > > kaanapali based boards.
> >
> > I would like to highlight that when Linux/EFI is enabled, which is a
> > common config, efi_reboot is used as the primary reboot path (see
> > machine_restart). 

Yes but, only if EFI RESET RUNTIME service is enabled by UEFI.

efi_reboot(...) {
..
         if (!efi_rt_services_supported(EFI_RT_SUPPORTED_RESET_SYSTEM))
                  return;
..

> > As a result, the PSCI reboot hook is not invoked in
> > this scenario, assuming Qualcomm firmware provides EFI runtime
> > services. 

Currently EFI RUNTIME RESET service is not enabled on these firmware.

> > As a follow-up, it would therefore be beneficial to also
> > improve the EFI path to support such custom mode(s)...

Yes, and potentially linux should also have some control, if it wants to
go via efi reset path or the PSCI reset path.

thanks,
Shivendra

> I have not checked but we should probably put in a place a way for user
> space to check that PSCI is _not_ the reboot method that will be
> used, lest it would be allowed to send commands to the kernel that
> would be duly ignored.
>
> Need to go through the whole thing again before commenting any further.
>
> Thanks,
> Lorenzo
>
> > Regards,
> > Loic
> >
> >
> >
> > > These DT patches depend on PSCI SYSTEM_RESET2 support introduced in:
> > > https://lore.kernel.org/all/20260514-arm-psci-system_reset2-vendor-reboots-v22-0-28a5bde07483@xxxxxxxxxxxxxxxx/
> > >
> > > To: Bjorn Andersson <andersson@xxxxxxxxxx>
> > > To: Konrad Dybcio <konradybcio@xxxxxxxxxx>
> > > To: Rob Herring <robh@xxxxxxxxxx>
> > > To: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
> > > To: Conor Dooley <conor+dt@xxxxxxxxxx>
> > > Cc: Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
> > > Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> > > Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> > > Cc: devicetree@xxxxxxxxxxxxxxx
> > > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > >
> > > Signed-off-by: Anurag Pateriya <anurag.pateriya@xxxxxxxxxxxxxxxx>
> > > ---
> > > Changes in v2:
> > > - Fixed subject lines.
> > > - Link to v1: https://lore.kernel.org/r/20260529-psci_sys_reset-dt-changes-for-pakala-v1-0-7c32161cf50b@xxxxxxxxxxxxxxxx
> > >
> > > ---
> > > Anurag Pateriya (1):
> > >        arm64: dts: qcom: sm8750: add reboot-mode support
> > >
> > > Xin Liu (1):
> > >        arm64: dts: qcom: kaanapali: add reboot-mode support
> > >
> > >   arch/arm64/boot/dts/qcom/kaanapali-mtp.dts | 7 +++++++
> > >   arch/arm64/boot/dts/qcom/kaanapali-qrd.dts | 7 +++++++
> > >   arch/arm64/boot/dts/qcom/kaanapali.dtsi    | 2 +-
> > >   arch/arm64/boot/dts/qcom/sm8750-mtp.dts    | 7 +++++++
> > >   arch/arm64/boot/dts/qcom/sm8750-qrd.dts    | 7 +++++++
> > >   arch/arm64/boot/dts/qcom/sm8750.dtsi       | 2 +-
> > >   6 files changed, 30 insertions(+), 2 deletions(-)
> > > ---
> > > base-commit: 6ee02bbf328be8a8586487e3af73b65a906cce58
> > > change-id: 20260529-psci_sys_reset-dt-changes-for-pakala-a09fc0e2a8a8
> > >
> > > Best regards,
> > > --
> > > Anurag Pateriya <anurag.pateriya@xxxxxxxxxxxxxxxx>