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* [PATCH] drm/i915/gsc: Fix the Driver-FLR completion
@ 2023-02-22 21:01 ` Alan Previn
  0 siblings, 0 replies; 14+ messages in thread
From: Alan Previn @ 2023-02-22 21:01 UTC (permalink / raw)
  To: intel-gfx
  Cc: Alan Previn, Vivi, Anshuman, dri-devel, Gupta,
	Daniele Ceraolo Spurio, Rodrigo

The Driver-FLR flow may inadvertently exit early before the full
completion of the re-init of the internal HW state if we only poll
GU_DEBUG Bit31 (polling for it to toggle from 0 -> 1). Instead
we need a two-step completion wait-for-completion flow that also
involves GU_CNTL. See the patch and new code comments for detail.
This is new direction from HW architecture folks.

   v2: - Add error message for the teardown timeout (Anshuman)
       - Don't duplicate code in comments (Jani)

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Fixes: 5a44fcd73498 ("drm/i915/gsc: Do a driver-FLR on unload if GSC was loaded")
---
 drivers/gpu/drm/i915/intel_uncore.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index f018da7ebaac..f3c46352db89 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -2749,14 +2749,25 @@ static void driver_initiated_flr(struct intel_uncore *uncore)
 	/* Trigger the actual Driver-FLR */
 	intel_uncore_rmw_fw(uncore, GU_CNTL, 0, DRIVERFLR);
 
+	/* Wait for hardware teardown to complete */
+	ret = intel_wait_for_register_fw(uncore, GU_CNTL,
+					 DRIVERFLR_STATUS, 0,
+					 flr_timeout_ms);
+	if (ret) {
+		drm_err(&i915->drm, "Driver-FLR-teardown wait completion failed! %d\n", ret);
+		return;
+	}
+
+	/* Wait for hardware/firmware re-init to complete */
 	ret = intel_wait_for_register_fw(uncore, GU_DEBUG,
 					 DRIVERFLR_STATUS, DRIVERFLR_STATUS,
 					 flr_timeout_ms);
 	if (ret) {
-		drm_err(&i915->drm, "wait for Driver-FLR completion failed! %d\n", ret);
+		drm_err(&i915->drm, "Driver-FLR-reinit wait completion failed! %d\n", ret);
 		return;
 	}
 
+	/* Clear sticky completion status */
 	intel_uncore_write_fw(uncore, GU_DEBUG, DRIVERFLR_STATUS);
 }
 
-- 
2.39.0


^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH] drm/i915/gsc: Fix the Driver-FLR completion
@ 2023-02-23 22:04 Alan Previn
  2023-02-23 23:35 ` Ceraolo Spurio, Daniele
  0 siblings, 1 reply; 14+ messages in thread
From: Alan Previn @ 2023-02-23 22:04 UTC (permalink / raw)
  To: intel-gfx
  Cc: Alan Previn, Vivi, Anshuman, dri-devel, Gupta,
	Daniele Ceraolo Spurio, Rodrigo

The Driver-FLR flow may inadvertently exit early before the full
completion of the re-init of the internal HW state if we only poll
GU_DEBUG Bit31 (polling for it to toggle from 0 -> 1). Instead
we need a two-step completion wait-for-completion flow that also
involves GU_CNTL. See the patch and new code comments for detail.
This is new direction from HW architecture folks.

   v2: - Add error message for the teardown timeout (Anshuman)
       - Don't duplicate code in comments (Jani)
   v3: - Add get/put runtime-pm for this function. Though
         not functionally required during unload, its so the uncore
	 doesn't complain.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Fixes: 5a44fcd73498 ("drm/i915/gsc: Do a driver-FLR on unload if GSC was loaded")
---
 drivers/gpu/drm/i915/intel_uncore.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index f018da7ebaac..9832b8ac8b1a 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -2724,10 +2724,13 @@ static void driver_initiated_flr(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore->i915;
 	const unsigned int flr_timeout_ms = 3000; /* specs recommend a 3s wait */
+	intel_wakeref_t wakeref;
 	int ret;
 
 	drm_dbg(&i915->drm, "Triggering Driver-FLR\n");
 
+	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
+
 	/*
 	 * Make sure any pending FLR requests have cleared by waiting for the
 	 * FLR trigger bit to go to zero. Also clear GU_DEBUG's DRIVERFLR_STATUS
@@ -2742,22 +2745,36 @@ static void driver_initiated_flr(struct intel_uncore *uncore)
 		drm_err(&i915->drm,
 			"Failed to wait for Driver-FLR bit to clear! %d\n",
 			ret);
-		return;
+		goto out;
 	}
 	intel_uncore_write_fw(uncore, GU_DEBUG, DRIVERFLR_STATUS);
 
 	/* Trigger the actual Driver-FLR */
 	intel_uncore_rmw_fw(uncore, GU_CNTL, 0, DRIVERFLR);
 
+	/* Wait for hardware teardown to complete */
+	ret = intel_wait_for_register_fw(uncore, GU_CNTL,
+					 DRIVERFLR_STATUS, 0,
+					 flr_timeout_ms);
+	if (ret) {
+		drm_err(&i915->drm, "Driver-FLR-teardown wait completion failed! %d\n", ret);
+		goto out;
+	}
+
+	/* Wait for hardware/firmware re-init to complete */
 	ret = intel_wait_for_register_fw(uncore, GU_DEBUG,
 					 DRIVERFLR_STATUS, DRIVERFLR_STATUS,
 					 flr_timeout_ms);
 	if (ret) {
-		drm_err(&i915->drm, "wait for Driver-FLR completion failed! %d\n", ret);
-		return;
+		drm_err(&i915->drm, "Driver-FLR-reinit wait completion failed! %d\n", ret);
+		goto out;
 	}
 
+	/* Clear sticky completion status */
 	intel_uncore_write_fw(uncore, GU_DEBUG, DRIVERFLR_STATUS);
+
+out:
+	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
 }
 
 /* Called via drm-managed action */
-- 
2.39.0


^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH] drm/i915/gsc: Fix the Driver-FLR completion
@ 2023-02-24  0:17 Alan Previn
  0 siblings, 0 replies; 14+ messages in thread
From: Alan Previn @ 2023-02-24  0:17 UTC (permalink / raw)
  To: intel-gfx
  Cc: Alan Previn, Vivi, Anshuman, dri-devel, Gupta,
	Daniele Ceraolo Spurio, Rodrigo, Vinay Belgaumkar

The Driver-FLR flow may inadvertently exit early before the full
completion of the re-init of the internal HW state if we only poll
GU_DEBUG Bit31 (polling for it to toggle from 0 -> 1). Instead
we need a two-step completion wait-for-completion flow that also
involves GU_CNTL. See the patch and new code comments for detail.
This is new direction from HW architecture folks.

   v2: - Add error message for the teardown timeout (Anshuman)
       - Don't duplicate code in comments (Jani)
   v3: - Add get/put runtime-pm for this function. Though
         not functionally required during unload, its so the uncore
	 doesn't complain.
   v4: - Remove the get/put runtime-pm - that was for a prior
         version of this patch (not needed for drm-managed callback).
       - Remove the fixes tag since this is only for MTL and MTL
         still needs force probe (Daniele).
       - Bit 31 of GU_CNTL should be DRIVERFLR instead of
         DRIVERFLR_STATUS (Daniele).

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Tested-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index f018da7ebaac..7b8fd3b7ff82 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -2749,14 +2749,25 @@ static void driver_initiated_flr(struct intel_uncore *uncore)
 	/* Trigger the actual Driver-FLR */
 	intel_uncore_rmw_fw(uncore, GU_CNTL, 0, DRIVERFLR);
 
+	/* Wait for hardware teardown to complete */
+	ret = intel_wait_for_register_fw(uncore, GU_CNTL,
+					 DRIVERFLR, 0,
+					 flr_timeout_ms);
+	if (ret) {
+		drm_err(&i915->drm, "Driver-FLR-teardown wait completion failed! %d\n", ret);
+		return;
+	}
+
+	/* Wait for hardware/firmware re-init to complete */
 	ret = intel_wait_for_register_fw(uncore, GU_DEBUG,
 					 DRIVERFLR_STATUS, DRIVERFLR_STATUS,
 					 flr_timeout_ms);
 	if (ret) {
-		drm_err(&i915->drm, "wait for Driver-FLR completion failed! %d\n", ret);
+		drm_err(&i915->drm, "Driver-FLR-reinit wait completion failed! %d\n", ret);
 		return;
 	}
 
+	/* Clear sticky completion status */
 	intel_uncore_write_fw(uncore, GU_DEBUG, DRIVERFLR_STATUS);
 }
 
-- 
2.39.0


^ permalink raw reply related	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2023-02-24  0:18 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-22 21:01 [PATCH] drm/i915/gsc: Fix the Driver-FLR completion Alan Previn
2023-02-22 21:01 ` [Intel-gfx] " Alan Previn
2023-02-22 21:53 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork
2023-02-22 23:16 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
2023-02-23  1:41 ` [Intel-gfx] [PATCH] " Belgaumkar, Vinay
2023-02-23 21:48 ` Teres Alexis, Alan Previn
2023-02-23 21:48   ` [Intel-gfx] " Teres Alexis, Alan Previn
2023-02-23 23:49 ` Ceraolo Spurio, Daniele
2023-02-23 23:49   ` [Intel-gfx] " Ceraolo Spurio, Daniele
2023-02-24  0:05   ` Teres Alexis, Alan Previn
2023-02-24  0:05     ` [Intel-gfx] " Teres Alexis, Alan Previn
2023-02-23 22:04 Alan Previn
2023-02-23 23:35 ` Ceraolo Spurio, Daniele
2023-02-24  0:17 Alan Previn

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