From: Kuogee Hsieh quic_khsieh@quicinc.com
[ Upstream commit 993a2adc6e2e94a0a7b5bfc054eda90ac95f62c3 ]
dp_catalog_ctrl_reset() will software reset DP controller. But it will not reset programmable registers to default value. DP driver still have to clear mask bits to interrupt status registers to disable interrupts after software reset of controller.
At current implementation, dp_ctrl_reset_irq_ctrl() will software reset dp controller but did not call dp_catalog_ctrl_enable_irq(false) to clear hpd related interrupt mask bits to disable hpd related interrupts due to it mistakenly think hpd related interrupt mask bits will be cleared by software reset of dp controller automatically. This mistake may cause system to crash during suspending procedure due to unexpected irq fired and trigger event thread to access dp controller registers with controller clocks are disabled.
This patch fixes system crash during suspending problem by removing "enable" flag condition checking at dp_ctrl_reset_irq_ctrl() so that hpd related interrupt mask bits are cleared to prevent unexpected from happening.
Changes in v2: -- add more details commit text
Changes in v3: -- add synchrons_irq() -- add atomic_t suspended
Changes in v4: -- correct Fixes's commit ID -- remove synchrons_irq()
Changes in v5: -- revise commit text
Changes in v6: -- add event_lock to protect "suspended"
Changes in v7: -- delete "suspended" flag
Fixes: 989ebe7bc446 ("drm/msm/dp: do not initialize phy until plugin interrupt received") Signed-off-by: Kuogee Hsieh quic_khsieh@quicinc.com Reviewed-by: Stephen Boyd swboyd@chromium.org Patchwork: https://patchwork.freedesktop.org/patch/486591/ Link: https://lore.kernel.org/r/1652804494-19650-1-git-send-email-quic_khsieh@quic... Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 6eb176872a17..7ae74bd05924 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1373,8 +1373,13 @@ 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)