From: Ville Syrj?l? <ville.syrj...@linux.intel.com>
drm_calc_timestamping_constants() makes the math more complex
than necessary.
- multipying the dotclock by 1000 is pointless, just makes all the
numbers bigger
- div64_u64() is also pointless, div_u64 is enough
- pixeldur_ns doesn't need any 64bit math
Signed-off-by: Ville Syrj?l? <ville.syrjala at linux.intel.com>
---
drivers/gpu/drm/drm_irq.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 48bf91f..d6ef034 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -451,10 +451,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
{
s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
- u64 dotclock;
-
- /* Dot clock in Hz: */
- dotclock = (u64) mode->clock * 1000;
+ int dotclock = mode->clock;
/* Fields of interlaced scanout modes are only halve a frame duration.
* Double the dotclock to get halve the frame-/line-/pixelduration.
@@ -464,17 +461,16 @@ void drm_calc_timestamping_constants(struct drm_crtc
*crtc,
/* Valid dotclock? */
if (dotclock > 0) {
- int frame_size;
- /* Convert scanline length in pixels and video dot clock to
- * line duration, frame duration and pixel duration in
- * nanoseconds:
+ int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
+
+ /*
+ * Convert scanline length in pixels and video
+ * dot clock to line duration, frame duration
+ * and pixel duration in nanoseconds:
*/
- pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
- linedur_ns = (s64) div64_u64(((u64) mode->crtc_htotal *
- 1000000000), dotclock);
- frame_size = mode->crtc_htotal * mode->crtc_vtotal;
- framedur_ns = (s64) div64_u64((u64) frame_size * 1000000000,
- dotclock);
+ pixeldur_ns = 1000000 / dotclock;
+ linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000,
dotclock);
+ framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
} else
DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
crtc->base.id);
@@ -487,7 +483,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc,
crtc->base.id, mode->crtc_htotal,
mode->crtc_vtotal, mode->crtc_vdisplay);
DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
- crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
+ crtc->base.id, dotclock, (int) framedur_ns,
(int) linedur_ns, (int) pixeldur_ns);
}
EXPORT_SYMBOL(drm_calc_timestamping_constants);
--
1.8.1.5
