linux-kernel - Re: [PATCH v3 3/7] drm/msm/dp: use drm_bridge_hpd

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Date:   Mon, 18 Sep 2023 13:16:16 -0700
From:   Kuogee Hsieh <quic_khsieh@...cinc.com>
To:     Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
CC:     <dri-devel@...ts.freedesktop.org>, <robdclark@...il.com>,
        <sean@...rly.run>, <swboyd@...omium.org>, <dianders@...omium.org>,
        <vkoul@...nel.org>, <daniel@...ll.ch>, <airlied@...il.com>,
        <agross@...nel.org>, <andersson@...nel.org>,
        <quic_abhinavk@...cinc.com>, <quic_jesszhan@...cinc.com>,
        <quic_sbillaka@...cinc.com>, <marijn.suijten@...ainline.org>,
        <freedreno@...ts.freedesktop.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 3/7] drm/msm/dp: use drm_bridge_hpd_notify() to report
 HPD status changes


On 9/15/2023 5:41 PM, Dmitry Baryshkov wrote:
> On Sat, 16 Sept 2023 at 00:38, Kuogee Hsieh <quic_khsieh@...cinc.com> wrote:
>> Currently DP driver use drm_helper_hpd_irq_event(), bypassing drm bridge
>> framework, to report HPD status changes to user space frame work.
>> Replace it with drm_bridge_hpd_notify() since DP driver is part of drm
>> bridge.
>>
>> Signed-off-by: Kuogee Hsieh <quic_khsieh@...cinc.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
>
> Also see the comment below.
>
>> ---
>>   drivers/gpu/drm/msm/dp/dp_display.c | 20 ++------------------
>>   1 file changed, 2 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>> index 18d16c7..59f9d85 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>> @@ -356,26 +356,10 @@ static bool dp_display_is_sink_count_zero(struct dp_display_private *dp)
>>                  (dp->link->sink_count == 0);
>>   }
>>
>> -static void dp_display_send_hpd_event(struct msm_dp *dp_display)
>> -{
>> -       struct dp_display_private *dp;
>> -       struct drm_connector *connector;
>> -
>> -       dp = container_of(dp_display, struct dp_display_private, dp_display);
>> -
>> -       connector = dp->dp_display.connector;
>> -       drm_helper_hpd_irq_event(connector->dev);
>> -}
>> -
>>   static int dp_display_send_hpd_notification(struct dp_display_private *dp,
>>                                              bool hpd)
>>   {
>> -       if ((hpd && dp->dp_display.link_ready) ||
>> -                       (!hpd && !dp->dp_display.link_ready)) {
>> -               drm_dbg_dp(dp->drm_dev, "HPD already %s\n",
>> -                               (hpd ? "on" : "off"));
>> -               return 0;
>> -       }
>> +       struct drm_bridge *bridge = dp->dp_display.bridge;
>>
>>          /* reset video pattern flag on disconnect */
>>          if (!hpd)
> Note, this part (resetting the video_test and setting of is_connected)
> should be moved to the dp_bridge_hpd_notify() too. Please ignore this
> comment if this is handled later in the series.

I think keep them here is better since eDP does not populate hpd_enable, 
hpd_disable and hpd_notify at edp_bridge_ops at drm_bridge_attach().

Keep them here will work for both eDP and DP.


>
>
>> @@ -385,7 +369,7 @@ static int dp_display_send_hpd_notification(struct dp_display_private *dp,
>>
>>          drm_dbg_dp(dp->drm_dev, "type=%d hpd=%d\n",
>>                          dp->dp_display.connector_type, hpd);
>> -       dp_display_send_hpd_event(&dp->dp_display);
>> +       drm_bridge_hpd_notify(bridge, dp->dp_display.link_ready);
>>
>>          return 0;
>>   }
>> --
>> 2.7.4
>>
>