Re: [PATCH] drm/msm/dp: Shorten SETUP timeout

From: Stephen Boyd
Date: Tue Oct 05 2021 - 19:35:38 EST


Quoting khsieh@xxxxxxxxxxxxxx (2021-10-05 16:04:40)
> On 2021-10-05 15:36, Stephen Boyd wrote:
> > Quoting Bjorn Andersson (2021-10-05 14:40:38)
> >> On Tue 05 Oct 11:45 PDT 2021, Stephen Boyd wrote:
> >>
> >> > Quoting Bjorn Andersson (2021-10-04 19:37:50)
> >> > > Found in the middle of a patch from Sankeerth was the reduction of the
> >> > > INIT_SETUP timeout from 10s to 100ms. Upon INIT_SETUP timeout the host
> >> > > is initalized and HPD interrupt start to be serviced, so in the case of
> >> > > eDP this reduction improves the user experience dramatically - i.e.
> >> > > removes 9.9s of bland screen time at boot.
> >> > >
> >> > > Suggested-by: Sankeerth Billakanti <sbillaka@xxxxxxxxxxxxxx>
> >> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> >> > > ---
> >> >
> >> > Any Fixes tag? BTW, the delay design is pretty convoluted. I had to go
> >> > re-read the code a couple times to understand that it's waiting 100ms
> >> > times the 'delay' number. Whaaaaat?
> >> >
> >>
> >> I assume you're happy with the current 10s delay on the current
> >> devices, so I don't think we should push for this to be backported.
> >> I have no need for it to be backported on my side at least.
> >>
> >
> > Sure. Fixes tag != backported to stable trees but it is close.
> >
> >> > Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> >>
> dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 1); <== to 100ms
>
> This patch will prevent usb3 from working due to dp driver initialize
> phy earlier than usb3 which cause timeout error at power up usb3 phy
> when both edp and dp are enabled.

That sounds pretty bad.

> I had prepared a patch (drm/msm/dp: do not initialize combo phy until
> plugin interrupt) to fix this problem.

Great! When were you planning to report this problem on the list?

> Unfortunately, my patch is depend on Bjorn's patch (PATCH v3 3/5]
> drm/msm/dp: Support up to 3 DP controllers).
> I will submit my patch for review once Bjorn's patches merged in.
> Therefore I would think this patch should go after both Bjorn's patches
> and my patch.
>

Why can't you send it now? Point to the other patch series as a
dependency.