[Intel-gfx] [PATCH] drm/i915: Report an error when i915.reset prevents a reset

[Chris Wilson]

If the user disables the GPU reset using the i915.reset parameter and
one occurs, report that we failed to reset the GPU. If we return early,
as we currently do, then we leave all state intact (with a hung GPU)
and clients block forever waiting for their requests to complete.

Testcase: igt/gem_eio
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_dma.c     | 1 -
 drivers/gpu/drm/i915/i915_drv.c     | 3 ---
 drivers/gpu/drm/i915/intel_uncore.c | 3 +++
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 88795d2f1819..c5349fa3fcce 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -165,7 +165,6 @@ static int i915_getparam(struct drm_device *dev, void *data,
 		break;
 	case I915_PARAM_HAS_GPU_RESET:
 		value = i915.enable_hangcheck &&
-			i915.reset &&
 			intel_has_gpu_reset(dev);
 		break;
 	default:
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 78ef0bb53c36..25ffe8afe744 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -863,9 +863,6 @@ int i915_reset(struct drm_device *dev)
 	bool simulated;
 	int ret;
 
-	if (!i915.reset)
-		return 0;
-
 	intel_reset_gt_powersave(dev);
 
 	mutex_lock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 4a86cf007aa0..f8e75def1a1d 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1457,6 +1457,9 @@ static int gen6_do_reset(struct drm_device *dev)
 
 static int (*intel_get_gpu_reset(struct drm_device *dev))(struct drm_device *)
 {
+	if (!i915.reset)
+		return NULL;
+
 	if (INTEL_INFO(dev)->gen >= 6)
 		return gen6_do_reset;
 	else if (IS_GEN5(dev))
-- 
2.1.4