Re: [PATCH 3/7] rtc: pm8xxx: add support for uefi offset

Johan Hovold
2025-01-20T15:15:50Z

On Mon, Jan 20, 2025 at 03:10:24PM +0000, Sudeep Holla wrote:
> On Mon, Jan 20, 2025 at 03:41:48PM +0100, Johan Hovold wrote:
> > 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 the
> > driver can take into account.
> >
> > Add support for storing a 32-bit offset from the GPS time epoch in a
> > UEFI variable so that the RTC time can be set on such platforms.
> >
>
> Why can't the UEFI runtime services be used here ?
> In short, why is drivers/rtc/rtc-efi.c not working or no attempts are
> made to check if that works just fine ?

As I alluded to in the commit message, the Qualcomm UEFI implementation
is broken and the runtime services cannot be accessed during runtime...

That's why we can't use rtc-efi and why we have a dedicated efivars
implementation that talks directly to the firmware using a custom
protocol:

https://lore.kernel.org/all/20220723224949.1089973-1-luzmaximilian@gmail.com/

Johan