drm/vblank: Switch drm_driver->get_vblank_timestamp to return a bool

There's really no reason for anything more:
- Calling this while the crtc vblank stuff isn't set up is a driver
  bug. Those places alrready DRM_ERROR.
- Calling this when the crtc is off is either a driver bug (calling
  drm_crtc_handle_vblank at the wrong time) or a core bug (for
  anything else). Again, we DRM_ERROR.
- EINVAL is checked at higher levels already, and if we'd use struct
  drm_crtc * instead of (dev, pipe) it would be real obvious that
  those are again core bugs.

The only valid failure mode is crap hardware that couldn't sample a
useful timestamp, to ask the core to just grab a not-so-accurate
timestamp. Bool is perfectly fine for that.

v2: Also fix up the one caller, I lost that in the shuffling (Jani).

v3: Fixup commit message (Neil).

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Cc: Eric Anholt <eric@anholt.net>
Cc: Rob Clark <robdclark@gmail.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-1-daniel.vetter@ffwll.ch

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index e3e7cb1d10a2..535969d74f64 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -869,25 +869,25 @@ void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
  *
  * Gets the timestamp on the requested crtc based on the
  * scanout position.  (all asics).
- * Returns postive status flags on success, negative error on failure.
+ * Returns true on success, false on failure.
  */
-int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
-				    int *max_error,
-				    struct timeval *vblank_time,
-				    unsigned flags)
+bool radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
+				     int *max_error,
+				     struct timeval *vblank_time,
+				     unsigned flags)
 {
 	struct drm_crtc *drmcrtc;
 	struct radeon_device *rdev = dev->dev_private;
 
 	if (crtc < 0 || crtc >= dev->num_crtcs) {
 		DRM_ERROR("Invalid crtc %d\n", crtc);
-		return -EINVAL;
+		return false;
 	}
 
 	/* Get associated drm_crtc: */
 	drmcrtc = &rdev->mode_info.crtcs[crtc]->base;
 	if (!drmcrtc)
-		return -EINVAL;
+		return false;
 
 	/* Helper routine in DRM core does all the work: */
 	return drm_calc_vbltimestamp_from_scanoutpos(dev, crtc, max_error,