Re: [PATCH v11 1/4] drm/msm/dp: do not initialize phy until plugin interrupt received

From: Stephen Boyd <swboyd@chromium.org>
To: Kuogee Hsieh <quic_khsieh@quicinc.com>,
	agross@kernel.org, airlied@linux.ie, bjorn.andersson@linaro.org,
	daniel@ffwll.ch, dmitry.baryshkov@linaro.org,
	dri-devel@lists.freedesktop.org, robdclark@gmail.com,
	sean@poorly.run, vkoul@kernel.org
Cc: quic_abhinavk@quicinc.com, aravindh@codeaurora.org,
	quic_sbillaka@quicinc.com, freedreno@lists.freedesktop.org,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v11 1/4] drm/msm/dp: do not initialize phy until plugin interrupt received
Date: Thu, 13 Jan 2022 11:47:51 -0800	[thread overview]
Message-ID: <CAE-0n51QbJHnOses5sF6xECR0gRZB1Fbi1KqoLG+61ZWH9BtOA@mail.gmail.com> (raw)
In-Reply-To: <338ae657-e8ed-e620-0aa7-4ad05df18ad1@quicinc.com>

Quoting Kuogee Hsieh (2022-01-13 09:51:42)
>
> On 1/12/2022 8:13 PM, Stephen Boyd wrote:
> >>>> -       if (dp->usbpd->orientation == ORIENTATION_CC2)
> >>>> -               flip = true;
> >>>> +       dp_power_init(dp->power, false);
> >>>> +       dp_ctrl_reset_irq_ctrl(dp->ctrl, true);
> >>>> +
> >>>> +       /*
> >>>> +        * eDP is the embedded primary display and has its own phy
> >>>> +        * initialize phy immediately
> >>> Question still stands why we can't wait for hpd high from the eDP panel.
> >>> Also, I think "has its own phy" means that it's not part of a combo
> >>> USB+DP phy? Can you please clarify?
> >>>
> >>>> +        */
> >>>> +       if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP)
> >>>> +               dp_display_host_phy_init(dp);
> >>>>
> >>>> -       dp_power_init(dp->power, flip);
> >>>> -       dp_ctrl_host_init(dp->ctrl, flip, reset);
> >>>>           dp_aux_init(dp->aux);
> >>>>           dp->core_initialized = true;
> >>>>    }
> >>>> @@ -1306,20 +1330,23 @@ static int dp_pm_resume(struct device *dev)
> >>>>           dp->hpd_state = ST_DISCONNECTED;
> >>>>
> >>>>           /* turn on dp ctrl/phy */
> >>>> -       dp_display_host_init(dp, true);
> >>>> +       dp_display_host_init(dp);
> >>>>
> >>>>           dp_catalog_ctrl_hpd_config(dp->catalog);
> >>>>
> >>>> -       /*
> >>>> -        * set sink to normal operation mode -- D0
> >>>> -        * before dpcd read
> >>>> -        */
> >>>> -       dp_link_psm_config(dp->link, &dp->panel->link_info, false);
> >>>>
> >>>>           if (dp_catalog_link_is_connected(dp->catalog)) {
> >>>> +               /*
> >>>> +                * set sink to normal operation mode -- D0
> >>>> +                * before dpcd read
> >>>> +                */
> >>>> +               dp_display_host_phy_init(dp);
> >>>> +               dp_link_psm_config(dp->link, &dp->panel->link_info, false);
> >>>>                   sink_count = drm_dp_read_sink_count(dp->aux);
> >>>>                   if (sink_count < 0)
> >>>>                           sink_count = 0;
> >>>> +
> >>>> +               dp_display_host_phy_exit(dp);
> >>> Why is the phy exited on resume when the link is still connected? Is
> >>> this supposed to be done only when the sink_count is 0? And how does
> >>> this interact with eDP where the phy is initialized by the call to
> >>> dp_display_host_init() earlier in this function.
> >>>
> >>>>           }
> >>>>
> >>>>           dp->link->sink_count = sink_count;
> > Any response to the above two comments?

??