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drm: Change {pixel,line,frame}dur_ns from s64 to int 

Using s64 for the timestamping constants is wasteful. Signed 32bit
integers get us a range of over +-2 seconds. Presuming that no-one
wants to a vrefresh rate less than 0.5, we can switch to using int
for the timestamping constants. We save a few bytes in drm_crtc and
avoid a bunch of 64bit math.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
This commit is contained in:
Ville Syrjälä 2013-10-26 17:38:52 +03:00
parent 77666b7226
commit 3c184f6991
2 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/gpu/drm/drm_irq.c
View File

@ -450,7 +450,7 @@ int drm_control(struct drm_device *dev, void *data,
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;
int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
int dotclock = mode->crtc_clock;
/* Fields of interlaced scanout modes are only half a frame duration.
@ -483,8 +483,8 @@ 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, dotclock, (int) framedur_ns,
(int) linedur_ns, (int) pixeldur_ns);
crtc->base.id, dotclock, framedur_ns,
linedur_ns, pixeldur_ns);
}
EXPORT_SYMBOL(drm_calc_timestamping_constants);
@ -544,7 +544,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
struct timeval tv_etime;
int vbl_status, vtotal, vdisplay;
int vpos, hpos, i;
s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
bool invbl;
if (crtc < 0 || crtc >= dev->num_crtcs) {
@ -607,18 +607,18 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
/* Accept result with < max_error nsecs timing uncertainty. */
if (duration_ns <= (s64) *max_error)
if (duration_ns <= *max_error)
break;
}
/* Noisy system timing? */
if (i == DRM_TIMESTAMP_MAXRETRIES) {
DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
crtc, (int) duration_ns/1000, *max_error/1000, i);
crtc, duration_ns/1000, *max_error/1000, i);
}
/* Return upper bound of timestamp precision error. */
*max_error = (int) duration_ns;
*max_error = duration_ns;
/* Check if in vblank area:
* vpos is >=0 in video scanout area, but negative
@ -631,7 +631,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
* since start of scanout at first display scanline. delta_ns
* can be negative if start of scanout hasn't happened yet.
*/
delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
/* Is vpos outside nominal vblank area, but less than
* 1/100 of a frame height away from start of vblank?
@ -669,7 +669,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
crtc, (int)vbl_status, hpos, vpos,
(long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
(long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
(int)duration_ns/1000, i);
duration_ns/1000, i);
vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
if (invbl)

2
include/drm/drm_crtc.h
View File

@ -447,7 +447,7 @@ struct drm_crtc {
uint16_t *gamma_store;
/* Constants needed for precise vblank and swap timestamping. */
s64 framedur_ns, linedur_ns, pixeldur_ns;
int framedur_ns, linedur_ns, pixeldur_ns;
/* if you are using the helper */
void *helper_private;