Re: [PATCH 2/2] drm/msm/dp: unplug interrupt missed after irq_hpd handler

[khsieh]

On 2021-01-11 11:54, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2021-01-07 12:30:25)
> > There is HPD unplug interrupts missed at scenario of an irq_hpd
> > followed by unplug interrupts with around 10 ms in between.
> > Since both AUX_SW_RESET and DP_SW_RESET clear pending HPD interrupts,
> > irq_hpd handler should not issues either aux or sw reset to avoid
> > following unplug interrupt be cleared accidentally.
>
> So the problem is that we're resetting the DP aux phy in the middle of
> the HPD state machine transitioning states?
yes, after reset aux, hw clear pending hpd interrupts
> > Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
> > ---
> > diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c 
> > b/drivers/gpu/drm/msm/dp/dp_catalog.c
> > index 44f0c57..9c0ce98 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> > @@ -190,6 +190,18 @@ int dp_catalog_aux_clear_hw_interrupts(struct 
> > dp_catalog *dp_catalog)
> >         return 0;
> >  }
> >
> > +/**
> > + * dp_catalog_aux_reset() - reset AUX controller
> > + *
> > + * @aux: DP catalog structure
> > + *
> > + * return: void
> > + *
> > + * This function reset AUX controller
> > + *
> > + * NOTE: reset AUX controller will also clear any pending HPD related 
> > interrupts
> > + *
> > + */
> >  void dp_catalog_aux_reset(struct dp_catalog *dp_catalog)
> >  {
> >         u32 aux_ctrl;
> > @@ -483,6 +495,18 @@ int dp_catalog_ctrl_set_pattern(struct dp_catalog 
> > *dp_catalog,
> >         return 0;
> >  }
> >
> > +/**
> > + * dp_catalog_ctrl_reset() - reset DP controller
> > + *
> > + * @aux: DP catalog structure
>
> It's called dp_catalog though.
registers access are through dp_catalog_xxxx
> > + *
> > + * return: void
> > + *
> > + * This function reset DP controller
>
> resets the
>
> > + *
> > + * NOTE: reset DP controller will also clear any pending HPD related 
> > interrupts
> > + *
> > + */
> >  void dp_catalog_ctrl_reset(struct dp_catalog *dp_catalog)
> >  {
> >         u32 sw_reset;
> > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c 
> > b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > index e3462f5..f96c415 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > @@ -1296,7 +1296,8 @@ static int dp_ctrl_setup_main_link(struct 
> > dp_ctrl_private *ctrl,
> >          * transitioned to PUSH_IDLE. In order to start transmitting
> >          * a link training pattern, we have to first do soft reset.
> >          */
> > -       dp_catalog_ctrl_reset(ctrl->catalog);
> > +       if (*training_step != DP_TRAINING_NONE)
>
> Can we check for the positive value instead? i.e.
> DP_TRAINING_1/DP_TRAINING_2
>
> > +               dp_catalog_ctrl_reset(ctrl->catalog);
> >
> >         ret = dp_ctrl_link_train(ctrl, cr, training_step);