[PATCH] drm/i915: Do not disable preemption for resets

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

This is going to our trybot for some smoke testing so excuse the informal
commit message.

Later I realized that engine resets are done from the normal and tasklet
contexts so I can't really use the sleeping waits. Here I tried the non-
atomic wait which runs with preemption enabled and dropped the top-level
preempt_disable.

Lets see what happens in CI..

And not sure what to do about the udelays yet. It is not preemptible on
RT?

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
---
 drivers/gpu/drm/i915/gt/intel_reset.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index e2152f75ba2e..6916eba3bd33 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -167,13 +167,13 @@ static int i915_do_reset(struct intel_gt *gt,
 	/* Assert reset for at least 20 usec, and wait for acknowledgement. */
 	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 	udelay(50);
-	err = wait_for_atomic(i915_in_reset(pdev), 50);
+	err = _wait_for_atomic(i915_in_reset(pdev), 50, 0);
 
 	/* Clear the reset request. */
 	pci_write_config_byte(pdev, I915_GDRST, 0);
 	udelay(50);
 	if (!err)
-		err = wait_for_atomic(!i915_in_reset(pdev), 50);
+		err = _wait_for_atomic(!i915_in_reset(pdev), 50, 0);
 
 	return err;
 }
@@ -193,7 +193,7 @@ static int g33_do_reset(struct intel_gt *gt,
 	struct pci_dev *pdev = to_pci_dev(gt->i915->drm.dev);
 
 	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
-	return wait_for_atomic(g4x_reset_complete(pdev), 50);
+	return _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 }
 
 static int g4x_do_reset(struct intel_gt *gt,
@@ -210,7 +210,7 @@ static int g4x_do_reset(struct intel_gt *gt,
 
 	pci_write_config_byte(pdev, I915_GDRST,
 			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
-	ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
+	ret =  _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 	if (ret) {
 		GT_TRACE(gt, "Wait for media reset failed\n");
 		goto out;
@@ -218,7 +218,7 @@ static int g4x_do_reset(struct intel_gt *gt,
 
 	pci_write_config_byte(pdev, I915_GDRST,
 			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
-	ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
+	ret =  _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 	if (ret) {
 		GT_TRACE(gt, "Wait for render reset failed\n");
 		goto out;
@@ -788,9 +788,7 @@ int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 		reset_mask = wa_14015076503_start(gt, engine_mask, !retry);
 
 		GT_TRACE(gt, "engine_mask=%x\n", reset_mask);
-		preempt_disable();
 		ret = reset(gt, reset_mask, retry);
-		preempt_enable();
 
 		wa_14015076503_end(gt, reset_mask);
 	}
-- 
2.39.2