Re: [PATCH v4] drm/msm/dp: power off DP phy at suspend

[Stephen Boyd]

Quoting Kuogee Hsieh (2021-06-02 09:43:05)
> Normal DP suspend operation contains two steps, display off followed
> by dp suspend, to complete system wide suspending cycle if display is
> up at that time. In this case, DP phy will be powered off at display
> off. However there is an exception case that depending on the timing
> of dongle plug in during system wide suspending, sometimes display off
> procedure may be skipped and dp suspend was called directly. In this
> case, dp phy is stay at powered on (phy->power_count = 1) so that at
> next resume dp driver crash at main link clock enable due to phy is
> not physically powered on. This patch will call dp_ctrl_off_link_stream()
> to tear down main link and power off phy at dp_pm_suspend() if main link
> had been brought up.
>
> Changes in V2:
> -- stashed changes into dp_ctrl.c
> -- add is_phy_on to monitor phy state
>
> Changes in V3:
> -- delete is_phy_on
> -- call dp_ctrl_off_link_stream() from dp_pm_suspend()
>
> Changes in V4:
> -- delete changes made at dp_power.c
> -- move main link status checking to dp_pm_suspend
>
> Fixes: 0114f31a2903 ("drm/msm/dp: handle irq_hpd with sink_count = 0 correctly)
> Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
> ---

Ok, this seems to work and is nice and small

Tested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>