Messages in this thread | | | Date | Wed, 04 Aug 2021 08:48:04 -0700 | From | khsieh@codeauro ... | Subject | Re: [PATCH v3] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume() |
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On 2021-08-03 12:05, Stephen Boyd wrote: > Quoting Kuogee Hsieh (2021-08-03 09:25:13) >> Currently at dp_pm_resume() is_connected state is decided base on hpd >> connection >> status only. This will put is_connected in wrongly "true" state at the >> scenario >> that dongle attached to DUT but without hmdi cable connecting to it. >> Fix this >> problem by adding read sink count from dongle and decided is_connected >> state base >> on both sink count and hpd connection status. >> >> Changes in v2: >> -- remove dp_get_sink_count() cand call drm_dp_read_sink_count() >> >> Changes in v3: >> -- delete status local variable from dp_pm_resume() >> >> Fixes: d9aa6571b28ba ("drm/msm/dp: check sink_count before update >> is_connected status") >> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> >> --- >> drivers/gpu/drm/msm/dp/dp_display.c | 18 +++++++++++++++--- >> 1 file changed, 15 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c >> b/drivers/gpu/drm/msm/dp/dp_display.c >> index 78c5301..0f39256 100644 >> --- a/drivers/gpu/drm/msm/dp/dp_display.c >> +++ b/drivers/gpu/drm/msm/dp/dp_display.c >> @@ -1313,7 +1313,7 @@ static int dp_pm_resume(struct device *dev) >> struct platform_device *pdev = to_platform_device(dev); >> struct msm_dp *dp_display = platform_get_drvdata(pdev); >> struct dp_display_private *dp; >> - u32 status; >> + int sink_count = 0; >> >> dp = container_of(dp_display, struct dp_display_private, >> dp_display); >> >> @@ -1327,14 +1327,26 @@ static int dp_pm_resume(struct device *dev) >> >> dp_catalog_ctrl_hpd_config(dp->catalog); >> >> - status = dp_catalog_link_is_connected(dp->catalog); >> + /* >> + * set sink to normal operation mode -- D0 >> + * before dpcd read >> + */ >> + dp_link_psm_config(dp->link, &dp->panel->link_info, false); >> + >> + /* if sink conencted, do dpcd read sink count */ > > s/conencted/connected/ > > This also just says what the code is doing. Why do we only read the > sink > count if the link is connected? Can we read the sink count even if the > link isn't connected and then consider sink count as 0 if trying to > read > fails? > yes, we can do that. But it will suffer aux time out and retry. i think it is better to avoid this overhead by check connection first.
>> + if (dp_catalog_link_is_connected(dp->catalog)) { >> + sink_count = drm_dp_read_sink_count(dp->aux); >> + if (sink_count < 0) >> + sink_count = 0; >> + } >> >> + dp->link->sink_count = sink_count; >> /* >> * can not declared display is connected unless >> * HDMI cable is plugged in and sink_count of >> * dongle become 1 >> */ >> - if (status && dp->link->sink_count) >> + if (dp->link->sink_count) >> dp->dp_display.is_connected = true; >> else >> dp->dp_display.is_connected = false;
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