[Freedreno] [PATCH] drm/msm/dsi: workaround for display enabled by bootloader

[Rob Clark]

On Tue, Oct 17, 2017 at 4:16 PM, Eric Anholt <eric at anholt.net> wrote:
> Rob Clark <robdclark at gmail.com> writes:
>
>> Bootloader enabled display, when the driver is built-in (rather than a
>> module loaded after CCF/genpd disable "unused" clocks/powerdomains)
>> causes problems since the driver thinks the clocks are off, but in fact
>> they are on.  This causes (for example) clk_set_rate() to fail.
>>
>> A better solution would be to support display handover from bootloader,
>> but that will require some CCF+genpd changes before that is possible.
>> So until then, we need this workaround.
>
> Hmm.  Couldn't the clk_set_rate() just turn off the clock and then make
> the rate change when there are no refs on the clk currently?

+sboyd

I *assume* the reasoning is something about parent clocks?

BR,
-R