diff options
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 128 |
1 files changed, 64 insertions, 64 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 65d2da9b604b..af965174b083 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -55,6 +55,70 @@ */ #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000 +/** + * drm_update_vblank_count - update the master vblank counter + * @dev: DRM device + * @crtc: counter to update + * + * Call back into the driver to update the appropriate vblank counter + * (specified by @crtc). Deal with wraparound, if it occurred, and + * update the last read value so we can deal with wraparound on the next + * call if necessary. + * + * Only necessary when going from off->on, to account for frames we + * didn't get an interrupt for. + * + * Note: caller must hold dev->vbl_lock since this reads & writes + * device vblank fields. + */ +static void drm_update_vblank_count(struct drm_device *dev, int crtc) +{ + u32 cur_vblank, diff, tslot, rc; + struct timeval t_vblank; + + /* + * Interrupts were disabled prior to this call, so deal with counter + * wrap if needed. + * NOTE! It's possible we lost a full dev->max_vblank_count events + * here if the register is small or we had vblank interrupts off for + * a long time. + * + * We repeat the hardware vblank counter & timestamp query until + * we get consistent results. This to prevent races between gpu + * updating its hardware counter while we are retrieving the + * corresponding vblank timestamp. + */ + do { + cur_vblank = dev->driver->get_vblank_counter(dev, crtc); + rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0); + } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc)); + + /* Deal with counter wrap */ + diff = cur_vblank - dev->vblank[crtc].last; + if (cur_vblank < dev->vblank[crtc].last) { + diff += dev->max_vblank_count; + + DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n", + crtc, dev->vblank[crtc].last, cur_vblank, diff); + } + + DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n", + crtc, diff); + + /* Reinitialize corresponding vblank timestamp if high-precision query + * available. Skip this step if query unsupported or failed. Will + * reinitialize delayed at next vblank interrupt in that case. + */ + if (rc) { + tslot = atomic_read(&dev->vblank[crtc].count) + diff; + vblanktimestamp(dev, crtc, tslot) = t_vblank; + } + + smp_mb__before_atomic(); + atomic_add(diff, &dev->vblank[crtc].count); + smp_mb__after_atomic(); +} + /* * Disable vblank irq's on crtc, make sure that last vblank count * of hardware and corresponding consistent software vblank counter @@ -799,70 +863,6 @@ void drm_send_vblank_event(struct drm_device *dev, int crtc, EXPORT_SYMBOL(drm_send_vblank_event); /** - * drm_update_vblank_count - update the master vblank counter - * @dev: DRM device - * @crtc: counter to update - * - * Call back into the driver to update the appropriate vblank counter - * (specified by @crtc). Deal with wraparound, if it occurred, and - * update the last read value so we can deal with wraparound on the next - * call if necessary. - * - * Only necessary when going from off->on, to account for frames we - * didn't get an interrupt for. - * - * Note: caller must hold dev->vbl_lock since this reads & writes - * device vblank fields. - */ -static void drm_update_vblank_count(struct drm_device *dev, int crtc) -{ - u32 cur_vblank, diff, tslot, rc; - struct timeval t_vblank; - - /* - * Interrupts were disabled prior to this call, so deal with counter - * wrap if needed. - * NOTE! It's possible we lost a full dev->max_vblank_count events - * here if the register is small or we had vblank interrupts off for - * a long time. - * - * We repeat the hardware vblank counter & timestamp query until - * we get consistent results. This to prevent races between gpu - * updating its hardware counter while we are retrieving the - * corresponding vblank timestamp. - */ - do { - cur_vblank = dev->driver->get_vblank_counter(dev, crtc); - rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0); - } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc)); - - /* Deal with counter wrap */ - diff = cur_vblank - dev->vblank[crtc].last; - if (cur_vblank < dev->vblank[crtc].last) { - diff += dev->max_vblank_count; - - DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n", - crtc, dev->vblank[crtc].last, cur_vblank, diff); - } - - DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n", - crtc, diff); - - /* Reinitialize corresponding vblank timestamp if high-precision query - * available. Skip this step if query unsupported or failed. Will - * reinitialize delayed at next vblank interrupt in that case. - */ - if (rc) { - tslot = atomic_read(&dev->vblank[crtc].count) + diff; - vblanktimestamp(dev, crtc, tslot) = t_vblank; - } - - smp_mb__before_atomic(); - atomic_add(diff, &dev->vblank[crtc].count); - smp_mb__after_atomic(); -} - -/** * drm_vblank_enable - enable the vblank interrupt on a CRTC * @dev: DRM device * @crtc: CRTC in question |