drm: Improve debug output for drm_wait_one_vblank

This replicates what we've done in i915 in

commit 31e4b89acbd7b19c9a8557e6e660a583a0b97daa
Author: Damien Lespiau <damien.lespiau@intel.com>
Date:   Mon Aug 18 13:51:00 2014 +0100

    drm/i915: Print the pipe on which the vblank wait times out

to make sure that when we switch i915 to drm_wait_one_vblank that the
debug output doesn't regress.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Thomas Wood <thomas.wood@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index e73cbda..5ef03c2 100644 (file)
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1077,7 +1077,7 @@ void drm_wait_one_vblank(struct drm_device *dev, int crtc)
        u32 last;
 
        ret = drm_vblank_get(dev, crtc);
-       if (WARN_ON(ret))
+       if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", crtc, ret))
                return;
 
        last = drm_vblank_count(dev, crtc);
@@ -1086,7 +1086,7 @@ void drm_wait_one_vblank(struct drm_device *dev, int crtc)
                                 last != drm_vblank_count(dev, crtc),
                                 msecs_to_jiffies(100));
 
-       WARN_ON(ret == 0);
+       WARN(ret == 0, "vblank wait timed out on crtc %i\n", crtc);
 
        drm_vblank_put(dev, crtc);
 }