| Message ID | 1651595136-24312-1-git-send-email-quic_khsieh@quicinc.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v3] drm/msm/dp: fix event thread stuck in wait_event after kthread_stop() | expand |
On 03/05/2022 19:25, Kuogee Hsieh wrote: > Event thread supposed to exit from its while loop after kthread_stop(). > However there may has possibility that event thread is pending in the > middle of wait_event due to condition checking never become true. > To make sure event thread exit its loop after kthread_stop(), this > patch OR kthread_should_stop() into wait_event's condition checking > so that event thread will exit its loop after kernal_stop(). > > Changes in v2: > -- correct spelling error at commit title > > Changes in v3: > -- remove unnecessary parenthesis > -- while(1) to replace while (!kthread_should_stop()) > > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Fixes: 570d3e5d28db ("drm/msm/dp: stop event kernel thread when DP unbind") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > drivers/gpu/drm/msm/dp/dp_display.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c > index c388323..da5c03a 100644 > --- a/drivers/gpu/drm/msm/dp/dp_display.c > +++ b/drivers/gpu/drm/msm/dp/dp_display.c > @@ -1103,15 +1103,20 @@ static int hpd_event_thread(void *data) > > dp_priv = (struct dp_display_private *)data; > > - while (!kthread_should_stop()) { > + while (1) { > if (timeout_mode) { > wait_event_timeout(dp_priv->event_q, > - (dp_priv->event_pndx == dp_priv->event_gndx), > - EVENT_TIMEOUT); > + (dp_priv->event_pndx == dp_priv->event_gndx) || > + kthread_should_stop(), EVENT_TIMEOUT); > } else { > wait_event_interruptible(dp_priv->event_q, > - (dp_priv->event_pndx != dp_priv->event_gndx)); > + (dp_priv->event_pndx != dp_priv->event_gndx) || > + kthread_should_stop()); > } > + > + if (kthread_should_stop()) > + break; > + > spin_lock_irqsave(&dp_priv->event_lock, flag); > todo = &dp_priv->event_list[dp_priv->event_gndx]; > if (todo->delay) {
On 03/05/2022 19:25, Kuogee Hsieh wrote: > Event thread supposed to exit from its while loop after kthread_stop(). > However there may has possibility that event thread is pending in the > middle of wait_event due to condition checking never become true. > To make sure event thread exit its loop after kthread_stop(), this > patch OR kthread_should_stop() into wait_event's condition checking > so that event thread will exit its loop after kernal_stop(). > > Changes in v2: > -- correct spelling error at commit title > > Changes in v3: > -- remove unnecessary parenthesis > -- while(1) to replace while (!kthread_should_stop()) > > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Fixes: 570d3e5d28db ("drm/msm/dp: stop event kernel thread when DP unbind") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> Let's do it properly: Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > drivers/gpu/drm/msm/dp/dp_display.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c > index c388323..da5c03a 100644 > --- a/drivers/gpu/drm/msm/dp/dp_display.c > +++ b/drivers/gpu/drm/msm/dp/dp_display.c > @@ -1103,15 +1103,20 @@ static int hpd_event_thread(void *data) > > dp_priv = (struct dp_display_private *)data; > > - while (!kthread_should_stop()) { > + while (1) { > if (timeout_mode) { > wait_event_timeout(dp_priv->event_q, > - (dp_priv->event_pndx == dp_priv->event_gndx), > - EVENT_TIMEOUT); > + (dp_priv->event_pndx == dp_priv->event_gndx) || > + kthread_should_stop(), EVENT_TIMEOUT); > } else { > wait_event_interruptible(dp_priv->event_q, > - (dp_priv->event_pndx != dp_priv->event_gndx)); > + (dp_priv->event_pndx != dp_priv->event_gndx) || > + kthread_should_stop()); > } > + > + if (kthread_should_stop()) > + break; > + > spin_lock_irqsave(&dp_priv->event_lock, flag); > todo = &dp_priv->event_list[dp_priv->event_gndx]; > if (todo->delay) {
Quoting Kuogee Hsieh (2022-05-03 09:25:36) > Event thread supposed to exit from its while loop after kthread_stop(). > However there may has possibility that event thread is pending in the > middle of wait_event due to condition checking never become true. > To make sure event thread exit its loop after kthread_stop(), this > patch OR kthread_should_stop() into wait_event's condition checking > so that event thread will exit its loop after kernal_stop(). > > Changes in v2: > -- correct spelling error at commit title > > Changes in v3: > -- remove unnecessary parenthesis > -- while(1) to replace while (!kthread_should_stop()) > > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Fixes: 570d3e5d28db ("drm/msm/dp: stop event kernel thread when DP unbind") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index c388323..da5c03a 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1103,15 +1103,20 @@ static int hpd_event_thread(void *data) dp_priv = (struct dp_display_private *)data; - while (!kthread_should_stop()) { + while (1) { if (timeout_mode) { wait_event_timeout(dp_priv->event_q, - (dp_priv->event_pndx == dp_priv->event_gndx), - EVENT_TIMEOUT); + (dp_priv->event_pndx == dp_priv->event_gndx) || + kthread_should_stop(), EVENT_TIMEOUT); } else { wait_event_interruptible(dp_priv->event_q, - (dp_priv->event_pndx != dp_priv->event_gndx)); + (dp_priv->event_pndx != dp_priv->event_gndx) || + kthread_should_stop()); } + + if (kthread_should_stop()) + break; + spin_lock_irqsave(&dp_priv->event_lock, flag); todo = &dp_priv->event_list[dp_priv->event_gndx]; if (todo->delay) {
Event thread supposed to exit from its while loop after kthread_stop(). However there may has possibility that event thread is pending in the middle of wait_event due to condition checking never become true. To make sure event thread exit its loop after kthread_stop(), this patch OR kthread_should_stop() into wait_event's condition checking so that event thread will exit its loop after kernal_stop(). Changes in v2: -- correct spelling error at commit title Changes in v3: -- remove unnecessary parenthesis -- while(1) to replace while (!kthread_should_stop()) Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Fixes: 570d3e5d28db ("drm/msm/dp: stop event kernel thread when DP unbind") Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> --- drivers/gpu/drm/msm/dp/dp_display.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)