[Intel-gfx] [PATCH] drm/i915: Don't fail rpm suspend with -EGAIN

[Daniel Vetter]

If we can't acquire dev->struct_mutex we need to fail runtime suspend,
at least with the current design. Currently we do that using -EAGAIN,
but that upsets the pm core, resulting in the occasional fail testcase
in our CI with the following dmesg dirt:

pci_pm_runtime_suspend(): intel_runtime_suspend+0x0/0x240 [i915] returns -11

Chris has some ideas to improve this, but for now just shut up the
error.

Cc: Paulo Zanoni <przanoni at gmail.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 5a70aca71d6b..ab8ffbc48e2d 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1497,8 +1497,7 @@ static int intel_runtime_suspend(struct device *device)
 	 * We could deadlock here in case another thread holding struct_mutex
 	 * calls RPM suspend concurrently, since the RPM suspend will wait
 	 * first for this RPM suspend to finish. In this case the concurrent
-	 * RPM resume will be followed by its RPM suspend counterpart. Still
-	 * for consistency return -EAGAIN, which will reschedule this suspend.
+	 * RPM resume will be followed by its RPM suspend counterpart.
 	 */
 	if (!mutex_trylock(&dev->struct_mutex)) {
 		DRM_DEBUG_KMS("device lock contention, deffering suspend\n");
@@ -1508,7 +1507,8 @@ static int intel_runtime_suspend(struct device *device)
 		 */
 		pm_runtime_mark_last_busy(device);
 
-		return -EAGAIN;
+		/* Fail silently to avoid upsetting the pm core. */
+		return 0;
 	}
 	/*
 	 * We are safe here against re-faults, since the fault handler takes
-- 
2.5.1