Messages in this thread | | | Date | Thu, 17 Sep 2020 16:20:48 -0700 | From | khsieh@codeauro ... | Subject | Re: [PATCH] drm/msm/dp: Sleep properly in dp_hpd_handler kthread |
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On 2020-09-17 15:44, Stephen Boyd wrote: > We shouldn't be waiting for an event here with a timeout of 100ms when > we're not in the 'timeout' arm of the if condition. Instead we should > be > sleeping in the interruptible state (S) until something happens and we > need to wakeup. Right now this kthread is running almost all the time > because it sleeps for 100ms, wakes up, sees there's nothing to do, and > then starts the process all over again. Looking at top it shows up in > the D state (uninterruptible) because it uses wait_event_timeout(). FIx > this up. > > Cc: Tanmay Shah <tanmay@codeaurora.org> > Cc: Kuogee Hsieh <khsieh@codeaurora.org> > Reported-by: Douglas Anderson <dianders@chromium.org> > Fixes: 8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on > Snapdragon Chipsets") > Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.org> > --- > > Based on msm-next-dp of https://gitlab.freedesktop.org/drm/msm.git > > drivers/gpu/drm/msm/dp/dp_display.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c > b/drivers/gpu/drm/msm/dp/dp_display.c > index 05a97e097edf..e175aa3fd3a9 100644 > --- a/drivers/gpu/drm/msm/dp/dp_display.c > +++ b/drivers/gpu/drm/msm/dp/dp_display.c > @@ -970,9 +970,8 @@ static int hpd_event_thread(void *data) > (dp_priv->event_pndx == dp_priv->event_gndx), > EVENT_TIMEOUT); > } else { > - wait_event_timeout(dp_priv->event_q, > - (dp_priv->event_pndx != dp_priv->event_gndx), > - EVENT_TIMEOUT); > + wait_event_interruptible(dp_priv->event_q, > + (dp_priv->event_pndx != dp_priv->event_gndx)); > } > spin_lock_irqsave(&dp_priv->event_lock, flag); > todo = &dp_priv->event_list[dp_priv->event_gndx]; > > base-commit: 937f941ca06f2f3ab64baebf31be2c16d57ae7b8
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