drm/i915: Remove nested work in gpu error handling
Now when we declare gpu errors only through our own dedicated
hangcheck workqueue there is no need to have a separate workqueue
for handling the resetting and waking up the clients as the deadlock
concerns are no more.
The only exception is i915_debugfs::i915_set_wedged, which triggers
error handling through process context. However as this is only used through
test harness it is responsibility for test harness not to introduce hangs
through both debug interface and through hangcheck mechanism at the same time.
Remove gpu_error.work and let the hangcheck work do the tasks it used to.
v2: Add a big warning sign into i915_debugfs::i915_set_wedged (Chris)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 3b332a4..211d494 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -3969,6 +3969,17 @@
struct drm_device *dev = data;
struct drm_i915_private *dev_priv = dev->dev_private;
+ /*
+ * There is no safeguard against this debugfs entry colliding
+ * with the hangcheck calling same i915_handle_error() in
+ * parallel, causing an explosion. For now we assume that the
+ * test harness is responsible enough not to inject gpu hangs
+ * while it is writing to 'i915_wedged'
+ */
+
+ if (i915_reset_in_progress(&dev_priv->gpu_error))
+ return -EAGAIN;
+
intel_runtime_pm_get(dev_priv);
i915_handle_error(dev, val,