Re: [edk2-devel] [PATCH 0/9] Platform/RaspberryPi: Utilize SPI flash for EFI variables

["Ard Biesheuvel" <ardb@kernel.org>]

On Thu, 2 Dec 2021 at 17:52, Jeremy Linton <jeremy.linton@arm.com> wrote:
>
> The RPi4 has a SPI flash with unused capacity. This set detects if
> that capacity is sufficient for a UEFI variable store and utilizes
> it as such. This fixes a long list of problems, and along the way likely
> also fixes a random boot failure caused by the FaultTolerantWriteDxe
> garbage collecting, and erasing the flash volume header which is being
> used to return information about the underlying variable storage capacity.
>
> This set was dependent on an earlier, mostly ignored set of changes to
> move the GPIO/etc devices into their own SSDT and disable them. Because
> of that, the two sets have been merged.
>
> Why is that? Because the SPI flash is mux'ed with the PWM used to play
> audio out the 3.5mm audio jack on this device. This causes a long list
> of problems we must try and avoid, starting with the fact that the pins
> need to be controlled by the uefi runtime service. The other problem is
> obviously that any time a variable is updated, if the user is utilizing
> the 3.5mm audio they will hear clicks and pops. Turns out that behavior
> isn't unique to this patch set because the low level boot/etc exhibits this
> when running in a TFA+uboot/edk2 environment. A fairly small tweak to TFA
> fixes the majority of this, and the remaining runtime problems caused
> by this patch actually are very slight and generally not noticeable unless
> one goes looking for them. OTOH, we revert to the earlier non persisted
> variable store if the firmware is running in a DT only mode, or the
> user enables the ACPI GPIO block.
>
>
> Jeremy Linton (9):
>   Platform/RaspberryPi: Cleanup menu visibility
>   Platform/RaspberryPi: Give the user control over the XHCI mailbox
>   Platform/RaspberryPi: Move GPIO/SPI/I2C to SSDT
>   Platform/RaspberryPi: Add menu item to enable/disable GPIO
>   Platform/RaspberryPi: Add constants for controlling SPI
>   Platform/RaspberryPi: Add mailbox cmd to control audio amp
>   Platform/RaspberryPi: Add SPI/GPIO to memory map
>   Platform/RaspberryPi: Allow pin function selection at runtime
>   Platform/RaspberryPi: Add SPI flash variable store.
>

Very nice!

I am having trouble applying these patches, though. Could you please
resend without the random whitespace changes?