From 2f9b5b3ae2eb625b75a898212a76f3b8c6d0d2b0 Mon Sep 17 00:00:00 2001 From: Kuogee Hsieh Date: Tue, 3 May 2022 09:25:36 -0700 Subject: [PATCH] drm/msm/dp: fix event thread stuck in wait_event after kthread_stop() 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 Fixes: 570d3e5d28db ("drm/msm/dp: stop event kernel thread when DP unbind") Signed-off-by: Kuogee Hsieh Reviewed-by: Dmitry Baryshkov Reviewed-by: Stephen Boyd Patchwork: https://patchwork.freedesktop.org/patch/484576/ Link: https://lore.kernel.org/r/1651595136-24312-1-git-send-email-quic_khsieh@quicinc.com Signed-off-by: Dmitry Baryshkov --- 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) { -- 2.7.4