Re: [Freedreno] [PATCH 1/5] clk: inherit clocks enabled by bootloader

From: Jeffrey Hugo
Date: Mon Jul 01 2019 - 14:03:05 EST


On Sun, Jun 30, 2019 at 9:02 AM Rob Clark <robdclark@xxxxxxxxx> wrote:
>
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> The goal here is to support inheriting a display setup by bootloader,
> although there may also be some non-display related use-cases.
>
> Rough idea is to add a flag for clks and power domains that might
> already be enabled when kernel starts, and which should not be
> disabled at late_initcall if the kernel thinks they are "unused".
>
> If bootloader is enabling display, and kernel is using efifb before
> real display driver is loaded (potentially from kernel module after
> userspace starts, in a typical distro kernel), we don't want to kill
> the clocks and power domains that are used by the display before
> userspace starts.
>
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>

Seems sane to me. I'm curious what Stephen Boyd thinks.
I'll try to give it a spin on one of the 835 laptops.

Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@xxxxxxxxx>