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

[Loic Poulain]

On Mon, Jun 15, 2026 at 3:09 PM Shivendra Pratap
<shivendra.pratap@xxxxxxxxxxxxxxxx> wrote:
>
>
>
> 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.

Okay, if the EFI/firmware does not expose it or ignores the reset
call, the PSCI hook will still be reached successfully. Thanks for the
clarification.


>
> >> 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>
> >>>
> >>>
>