Re: [PATCH] arm64: dts: qcom: sc7280: Set SPI flash to 50 MHz for herobrine boards

From: Matthias Kaehlcke
Date: Thu May 05 2022 - 20:48:08 EST


On Thu, May 05, 2022 at 04:14:30PM -0700, Douglas Anderson wrote:
> sc7280-herobrine based boards are specced to be able to access their
> SPI flash at 50 MHz with the drive strength of the pins set at 8. The
> drive strength is already set to 8 in "sc7280-herobrine.dtsi", so
> let's bump up the clock. The matching firmware change for this is at:
>
> https://review.coreboot.org/c/coreboot/+/63948
>
> NOTE: the firmware change isn't _required_ to make the kernel work at
> 50 MHz, it merely shows that the boards are known to work fine at 50
> MHz.
>
> ALSO NOTE: this doesn't update the "sc7280-chrome-common.dtsi" file
> which is used by both herobrine boards and IDP. At the moment the IDP
> boards aren't configuring a drive strength of 8 and it seems safer to
> just leave them at the slower speed if they're already working.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>