Re: [PATCH] arm64: dts: qcom: sc8280xp-blackrock: switch to uefi rtc offset

Johan Hovold
2025-02-28T07:48:08Z

Hi Jens,

On Wed, Jan 22, 2025 at 07:41:56AM +0100, Jens Glathe via B4 Relay wrote:
> From: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
>
> On many Qualcomm platforms the PMIC RTC control and time registers are
> read-only so that the RTC time can not be updated. Instead an offset
> needs be stored in some machine-specific non-volatile memory, which a
> driver can take into account.
>
> Switch to using the Qualcomm specific UEFI variable that is used by the
> UEFI firmware (and Windows) to store the RTC offset.
>
> This specifically means that the RTC time will be synchronised between
> the UEFI firmware setup (or UEFI shell), Windows and Linux.
>
> Note however that Windows stores the RTC time in local time by default,
> while Linux typically uses UTC (i.e. as on X86).
>
> Based on a patch by Johan Hovold. [1]
>
> Link: https://lore.kernel.org/all/20250120144152.11949-7-johan+linaro@kernel.org/ # [1]
> Signed-off-by: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
> ---
> This is a patch to switch the Windows Dev Kit 2023 over to
> using the UEFI offset.

Please try to avoid posting patches before their dependencies have been
merged, but at least mention any such dependencies in the cover letter
(or here under the --- line).

The series this patch depends on has now been superseded with a v2
dropping the DT property so this one will also need a respin once the
driver changes have been merged:

https://lore.kernel.org/all/20250219134118.31017-1-johan+linaro@kernel.org/

Johan