[PATCH] drm/msm/dsi: save PLL registers across first PHY reset

[Dmitry Baryshkov]

On Sat, 30 Jan 2021 at 05:00, Benjamin Li <benl at squareup.com> wrote:
>
>
> On 10/30/20 6:55 AM, Dmitry Baryshkov wrote:
> > Hello,
> >
> > On 07/10/2020 03:10, benl-kernelpatches at squareup.com wrote:
> >> From: Benjamin Li <benl at squareup.com>
> >>
> >> Take advantage of previously-added support for persisting PLL
> >> registers across DSI PHY disable/enable cycles (see 328e1a6
> >> 'drm/msm/dsi: Save/Restore PLL status across PHY reset') to
> >> support persisting across the very first DSI PHY enable at
> >> boot.
> >
> > Interesting enough, this breaks exactly on 8016. On DB410c with latest bootloader and w/o splash screen this patch causes boot freeze. Without this patch the board would successfully boot with display routed to HDMI.
>
> Hi Dimtry,
>
> Thanks for your fix for the DB410c breakage ("drm/msm/dsi: do not
> try reading 28nm vco rate if it's not enabled") that this patch
> causes.
>
> I re-tested my patch on top of qcom/linux for-next (3e6a8ce094759)
> which now has your fix, on a DB410c with HDMI display and no splash
> (which seems to be the default using the Linaro SD card image's LK),
> and indeed it is fixed.
>
> I assume you already also did the same & are okay with this going in.
> Appreciate the testing!

Tested-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Tested on RB5 and Dragonboard 845c (RB3).




-- 
With best wishes
Dmitry