There is a reboot/suspend test case where system suspend is forced
during system booting up. Since dp_display_host_init() of external
DP is executed at hpd thread context, this test case may created a
scenario that dp_display_host_deinit() from pm_suspend() run before
dp_display_host_init() if hpd thread has no chance to run during
booting up while suspend request command was issued. At this scenario
system will crash at aux register access at dp_display_host_deinit()
since aux clock had not yet been enabled by dp_display_host_init().
Therefore we have to ensure aux clock enabled by checking
core_initialized flag before access aux registers at pm_suspend.
Changes in v2:
-- at commit text, dp_display_host_init() instead of host_init()
-- at commit text, dp_display_host_deinit() instead of host_deinit()
Changes in v3:
-- re arrange to avoid commit text line over 75 chars
Fixes: 989ebe7bc446 ("drm/msm/dp: do not initialize phy until plugin interrupt received")
Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index bde1a7c..1850738 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -460,10 +460,12 @@ static void dp_display_host_init(struct dp_display_private *dp)
dp->dp_display.connector_type, dp->core_initialized,
dp->phy_initialized);
- dp_power_init(dp->power, false);
- dp_ctrl_reset_irq_ctrl(dp->ctrl, true);
- dp_aux_init(dp->aux);
- dp->core_initialized = true;
+ if (!dp->core_initialized) {
+ dp_power_init(dp->power, false);
+ dp_ctrl_reset_irq_ctrl(dp->ctrl, true);
+ dp_aux_init(dp->aux);
+ dp->core_initialized = true;
+ }
}
static void dp_display_host_deinit(struct dp_display_private *dp)
@@ -472,10 +474,12 @@ static void dp_display_host_deinit(struct dp_display_private *dp)
dp->dp_display.connector_type, dp->core_initialized,
dp->phy_initialized);
- dp_ctrl_reset_irq_ctrl(dp->ctrl, false);
- dp_aux_deinit(dp->aux);
- dp_power_deinit(dp->power);
- dp->core_initialized = false;
+ if (dp->core_initialized) {
+ dp_ctrl_reset_irq_ctrl(dp->ctrl, false);
+ dp_aux_deinit(dp->aux);
+ dp_power_deinit(dp->power);
+ dp->core_initialized = false;
+ }
}
static int dp_display_usbpd_configure_cb(struct device *dev)
--
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