[PATCH 10/17] drm/amd/display: fix system hang when PSR exits

David Zhang dingchen.zhang at amd.com
Thu May 5 14:23:16 UTC 2022


[why]
When DC driver send PSR exit dmub command to DMUB FW, it might not
wait until PSR exit. Then it may hit the following deadlock situation.
1. DC driver send HW LOCK command to DMUB FW due to frame update
2. DMUB FW Set the HW lock
3. DMUB execute PSR exit sequence and stuck at polling DPG Pending
register due to the HW Lock is set
4. DC driver ask DMUB FW to unlock HW lock, but DMUB FW is polling
DPG pending register

[how]
The reason why DC driver doesn't wait until PSR exit is because some of
the PSR state machine state is not update the dc driver. So when DC
driver read back the PSR state, it take the state for PSR inactive.

Signed-off-by: David Zhang <dingchen.zhang at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc_types.h     |  7 +++++++
 drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dc_types.h b/drivers/gpu/drm/amd/display/dc/dc_types.h
index 119ce8b7a555..144c387010c2 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_types.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_types.h
@@ -657,10 +657,17 @@ enum dc_psr_state {
 	PSR_STATE4b,
 	PSR_STATE4c,
 	PSR_STATE4d,
+	PSR_STATE4_FULL_FRAME,
+	PSR_STATE4a_FULL_FRAME,
+	PSR_STATE4b_FULL_FRAME,
+	PSR_STATE4c_FULL_FRAME,
+	PSR_STATE4_FULL_FRAME_POWERUP,
 	PSR_STATE5,
 	PSR_STATE5a,
 	PSR_STATE5b,
 	PSR_STATE5c,
+	PSR_STATE_HWLOCK_MGR,
+	PSR_STATE_POLLVUPDATE,
 	PSR_STATE_INVALID = 0xFF
 };
 
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
index c2d65756ce5d..e784002fe312 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -74,6 +74,22 @@ static enum dc_psr_state convert_psr_state(uint32_t raw_state)
 		state = PSR_STATE5b;
 	else if (raw_state == 0x53)
 		state = PSR_STATE5c;
+	else if (raw_state == 0x4A)
+		state = PSR_STATE4_FULL_FRAME;
+	else if (raw_state == 0x4B)
+		state = PSR_STATE4a_FULL_FRAME;
+	else if (raw_state == 0x4C)
+		state = PSR_STATE4b_FULL_FRAME;
+	else if (raw_state == 0x4D)
+		state = PSR_STATE4c_FULL_FRAME;
+	else if (raw_state == 0x4E)
+		state = PSR_STATE4_FULL_FRAME_POWERUP;
+	else if (raw_state == 0x60)
+		state = PSR_STATE_HWLOCK_MGR;
+	else if (raw_state == 0x61)
+		state = PSR_STATE_POLLVUPDATE;
+	else
+		state = PSR_STATE_INVALID;
 
 	return state;
 }
-- 
2.25.1



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