| Message ID | 1356570106-2263-1-git-send-email-djkurtz@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Dec 26, 2012 at 5:01 PM, Daniel Kurtz <djkurtz@chromium.org> wrote: > It is a bit more precise to compute the total number of pixels first and > then divide, rather than multiplying the line pixel count by the > already-rounded line duration. > > Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> > Ping? > --- > drivers/gpu/drm/drm_irq.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index 19c01ca..05c91e0 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -505,6 +505,7 @@ 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: > @@ -512,7 +513,10 @@ void drm_calc_timestamping_constants(struct drm_crtc > *crtc) > pixeldur_ns = (s64) div64_u64(1000000000, dotclock); > linedur_ns = (s64) div64_u64(((u64) > crtc->hwmode.crtc_htotal * > 1000000000), dotclock); > - framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns; > + frame_size = crtc->hwmode.crtc_htotal * > + crtc->hwmode.crtc_vtotal; > + framedur_ns = (s64) div64_u64((u64) frame_size * > 1000000000, > + dotclock); > } else > DRM_ERROR("crtc %d: Can't calculate constants, dotclock = > 0!\n", > crtc->base.id); > -- > 1.7.7.3 > >
On Wed, Dec 26, 2012 at 5:01 PM, Daniel Kurtz <djkurtz@chromium.org> wrote: > > It is a bit more precise to compute the total number of pixels first and > then divide, rather than multiplying the line pixel count by the > already-rounded line duration. > > Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Ping? > --- > drivers/gpu/drm/drm_irq.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index 19c01ca..05c91e0 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -505,6 +505,7 @@ 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: > @@ -512,7 +513,10 @@ void drm_calc_timestamping_constants(struct drm_crtc > *crtc) > pixeldur_ns = (s64) div64_u64(1000000000, dotclock); > linedur_ns = (s64) div64_u64(((u64) > crtc->hwmode.crtc_htotal * > 1000000000), dotclock); > - framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns; > + frame_size = crtc->hwmode.crtc_htotal * > + crtc->hwmode.crtc_vtotal; > + framedur_ns = (s64) div64_u64((u64) frame_size * > 1000000000, > + dotclock); > } else > DRM_ERROR("crtc %d: Can't calculate constants, dotclock = > 0!\n", > crtc->base.id); > -- > 1.7.7.3 >
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 19c01ca..05c91e0 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -505,6 +505,7 @@ 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: @@ -512,7 +513,10 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc) pixeldur_ns = (s64) div64_u64(1000000000, dotclock); linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal * 1000000000), dotclock); - framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns; + frame_size = crtc->hwmode.crtc_htotal * + crtc->hwmode.crtc_vtotal; + framedur_ns = (s64) div64_u64((u64) frame_size * 1000000000, + dotclock); } else DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n", crtc->base.id);
It is a bit more precise to compute the total number of pixels first and then divide, rather than multiplying the line pixel count by the already-rounded line duration. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> --- drivers/gpu/drm/drm_irq.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)