On 18/03/17 05:20 AM, Chris Wilson wrote:
> Move the repeated (a - b) <= (1 << 23) to its own function.
>
> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
> ---
> drivers/gpu/drm/drm_irq.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index a164cf51d093..253505da57bd 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -1492,6 +1492,11 @@ int drm_legacy_modeset_ctl(struct drm_device *dev,
> void *data,
> return 0;
> }
>
> +static inline bool vblank_passed(u32 seq, u32 ref)
> +{
> + return (seq - ref) <= (1 << 23);
> +}
As a followup, maybe we could try changing this to
return (s32)(seq - ref) >= 0;
> @@ -1542,7 +1547,7 @@ static int drm_queue_vblank_event(struct drm_device
> *dev, unsigned int pipe,
> vblwait->request.sequence);
>
> e->event.sequence = vblwait->request.sequence;
> - if ((seq - vblwait->request.sequence) <= (1 << 23)) {
> + if (vblank_passed(seq, vblwait->request.sequence)) {
> drm_vblank_put(dev, pipe);
> send_vblank_event(dev, e, seq, &now);
> vblwait->reply.sequence = seq;
> @@ -1632,9 +1637,8 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
> }
>
> if ((flags & _DRM_VBLANK_NEXTONMISS) &&
> - (seq - vblwait->request.sequence) <= (1 << 23)) {
> + vblank_passed(seq, vblwait->request.sequence))
> vblwait->request.sequence = seq + 1;
> - }
>
> if (flags & _DRM_VBLANK_EVENT) {
> /* must hold on to the vblank ref until the event fires
> @@ -1647,8 +1651,8 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
> DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
> vblwait->request.sequence, pipe);
> DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
> - (drm_vblank_count(dev, pipe) -
> - vblwait->request.sequence) <= (1 << 23) ||
> + vblank_passed(drm_vblank_count(dev, pipe),
> + vblwait->request.sequence) ||
> !READ_ONCE(vblank->enabled));
> }
>
>
There's another instance in drm_handle_vblank_events.
--
Earthling Michel Dänzer | http://www.amd.com
Libre software enthusiast | Mesa and X developer
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