[Intel-gfx] [PATCH v2] Fix pointer tests in error-handling paths

[Dave Gordon]

In the error-handling paths of i915_gem_do_execbuffer() and
intel_crtc_page_flip(), the local pointer-to-request variables
were expected to be either valid pointers or NULL. Since

   2682708 drm/i915: simplify allocation of driver-internal requests

they could also be ERR_PTR() values, so the tests need to be
updated to accommodate this case.

v2:	Added testcase (Chris Wilson)

Testcase: igt/gem_close_race
Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
  drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 +-
  drivers/gpu/drm/i915/intel_display.c       | 2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c 
b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 2dc08ce..a7bd555 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1654,7 +1654,7 @@ static bool only_mappable_for_reloc(unsigned int 
flags)
  	 * must be freed again. If it was submitted then it is being tracked
  	 * on the active request list and no clean up is required here.
  	 */
-	if (ret && req)
+	if (ret && !IS_ERR_OR_NULL(req))
  		i915_gem_request_cancel(req);

  	mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index 8104511..b88cdac 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11726,7 +11726,7 @@ static int intel_crtc_page_flip(struct drm_crtc 
*crtc,
  cleanup_unpin:
  	intel_unpin_fb_obj(fb, crtc->primary->state);
  cleanup_pending:
-	if (request)
+	if (!IS_ERR_OR_NULL(request))
  		i915_gem_request_cancel(request);
  	atomic_dec(&intel_crtc->unpin_work_count);
  	mutex_unlock(&dev->struct_mutex);
-- 
1.9.1