On 5/11/2022 6:03 PM, Dmitry Baryshkov wrote:
On Thu, 12 May 2022 at 04:01, Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
Quoting Dmitry Baryshkov (2022-05-11 17:41:50)
On 12/05/2022 03:02, Kuogee Hsieh wrote:
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index af7a80c..f3e333e 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1389,8 +1389,13 @@ void dp_ctrl_reset_irq_ctrl(struct dp_ctrl *dp_ctrl, bool enable)
dp_catalog_ctrl_reset(ctrl->catalog);
- if (enable)
- dp_catalog_ctrl_enable_irq(ctrl->catalog, enable);
+ /*
+ * all dp controller programmable registers will not
+ * be reset to default value after DP_SW_RESET
+ * therefore interrupt mask bits have to be updated
+ * to enable/disable interrupts
+ */
+ dp_catalog_ctrl_enable_irq(ctrl->catalog, enable);
}
void dp_ctrl_phy_init(struct dp_ctrl *dp_ctrl)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index c388323..79439b8 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -98,6 +98,8 @@ struct dp_display_private {
struct dp_ctrl *ctrl;
struct dp_debug *debug;
+ atomic_t suspended;
I think it'd be better to protect it with event_lock rather than using
atomics.
Agreed. I think the concern is that the event queue will have "stuff" in
it. If the event queue was all a threaded irq we could simply call
synchronize_irq() after disabling the irq bit in the DP hardware and
then we would know it is safe to power down the DP logic. Unfortunately
the event queue is a kthread so we can't do that and we have to rewrite
synchronize_irq() by checking that the event queue is empty and waiting
for it to empty out otherwise. It's not safe enough to simply do the
power operations underneath the event_lock because there's a queue in
the kthread that might be waiting to grab the event_lock to process.
This sounds like a good reason to rewrite event_thread to use
threaded_irq and/or workqueue.
ok, i will do
1) protect suspended flag with event_lock to prevent new event be added
2) disable interrupts
2) wait for event_q empty before turn off power
