Re: [PATCH v3 6/6] drm/msm/dp: Remove the hpd init delay for eDP

[khsieh]

On 2021-10-27 23:38, Stephen Boyd wrote:
> Quoting Sankeerth Billakanti (2021-10-27 18:54:48)
> > DP driver needs a 10 second delay before phy_init so that
> > the usb combo phy initializes and sets up the necessary
> > clocks for usb devices such as keyboard and mouse.
> >
> > eDP controller uses a standalone phy and need not wait for
> > phy initialization from any other component. This change
> > will remove the delay for eDP controller.
> >
> > Signed-off-by: Sankeerth Billakanti <quic_sbillaka@xxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/msm/dp/dp_display.c | 11 ++++++++++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c 
> > b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 61385d6..de6a1fd 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -1438,7 +1439,15 @@ void msm_dp_irq_postinstall(struct msm_dp 
> > *dp_display)
> >
> >         dp_hpd_event_setup(dp);
> >
> > -       dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
> > +       if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP) {
> > +               /* eDP does not need any delay before phy init */
> > +               delay = 0;
> > +       } else {
> > +               /* DP needs 10 second delay to let usb combo phy 
> > initialize */
>
> This seems to be a different approach to the patch Kuogee sent a week 
> or
> two ago. Can we figure out what's wrong with the DP phy starting before
> the USB phy? I suppose this patch is OK as a temporary hack to keep
> moving with eDP, but we really need to figure out what's wrong with DP
> so this delay can be removed entirely. Has any progress been made on
> that?
Sankeerth,
Can you drop this patch for now.
Let's discuss more.

> > +               delay = 100;
> > +       }
> > +
> > +       dp_add_event(dp, EV_HPD_INIT_SETUP, 0, delay);