From: Ville Syrjälä ville.syrjala@linux.intel.com
On i965gm we need to adjust max_vblank_count dynamically depending on whether the TV encoder is used or not. To that end add a per-crtc max_vblank_count that takes precedence over its device wide counterpart. The driver can now call drm_crtc_set_max_vblank_count() to configure the per-crtc value before calling drm_vblank_on().
Also looks like there was some discussion about exynos needing similar treatment.
Cc: stable@vger.kernel.org Cc: Inki Dae inki.dae@samsung.com Cc: Daniel Vetter daniel@ffwll.ch Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_vblank.c | 39 ++++++++++++++++++++++++++++++++---- include/drm/drm_vblank.h | 8 ++++++++ 2 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 98e091175921..c3abbdca8aba 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -105,13 +105,20 @@ static void store_vblank(struct drm_device *dev, unsigned int pipe, write_sequnlock(&vblank->seqlock); }
+static u32 drm_max_vblank_count(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + return vblank->max_vblank_count ?: dev->max_vblank_count; +} + /* * "No hw counter" fallback implementation of .get_vblank_counter() hook, * if there is no useable hardware frame counter available. */ static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe) { - WARN_ON_ONCE(dev->max_vblank_count != 0); + WARN_ON_ONCE(drm_max_vblank_count(dev, pipe) != 0); return 0; }
@@ -198,6 +205,7 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, ktime_t t_vblank; int count = DRM_TIMESTAMP_MAXRETRIES; int framedur_ns = vblank->framedur_ns; + u32 max_vblank_count = drm_max_vblank_count(dev, pipe);
/* * Interrupts were disabled prior to this call, so deal with counter @@ -216,9 +224,9 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, in_vblank_irq); } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
- if (dev->max_vblank_count != 0) { + if (max_vblank_count) { /* trust the hw counter when it's around */ - diff = (cur_vblank - vblank->last) & dev->max_vblank_count; + diff = (cur_vblank - vblank->last) & max_vblank_count; } else if (rc && framedur_ns) { u64 diff_ns = ktime_to_ns(ktime_sub(t_vblank, vblank->time));
@@ -258,7 +266,8 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, pipe, vblank->count, diff, cur_vblank, vblank->last);
if (diff == 0) { - WARN_ON_ONCE(cur_vblank != vblank->last); + WARN_ON_ONCE(max_vblank_count && + cur_vblank != vblank->last); return; }
@@ -1204,6 +1213,28 @@ void drm_crtc_vblank_reset(struct drm_crtc *crtc) } EXPORT_SYMBOL(drm_crtc_vblank_reset);
+/** + * drm_crtc_set_max_vblank_count - configure the hw max vblank counter value + * @crtc: CRTC in question + * @max_vblank_count: max hardware vblank counter value + * + * Update the maximum hardware vblank counter value for @crtc. Useful + * for hardware where the operation of the hardware vblank counter + * depends on the active display configuration. + * + * If used, must be called before drm_vblank_on(). + */ +void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, + u32 max_vblank_count) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + vblank->max_vblank_count = max_vblank_count; +} +EXPORT_SYMBOL(drm_crtc_set_max_vblank_count); + /** * drm_crtc_vblank_on - enable vblank events on a CRTC * @crtc: CRTC in question diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h index 6ad9630d4f48..ecb2cf9913e2 100644 --- a/include/drm/drm_vblank.h +++ b/include/drm/drm_vblank.h @@ -128,6 +128,12 @@ struct drm_vblank_crtc { * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. */ u32 last; + /** + * @max_vblank_count: Maximum value of the hardware vblank counter. + * If non-zero this takes precedence over &drm_device.max_vblank_count + * for this crtc. Otherwise &drm_device.max_vblank_count is used. + */ + u32 max_vblank_count; /** * @inmodeset: Tracks whether the vblank is disabled due to a modeset. * For legacy driver bit 2 additionally tracks whether an additional @@ -206,4 +212,6 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, void drm_calc_timestamping_constants(struct drm_crtc *crtc, const struct drm_display_mode *mode); wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); +void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, + u32 max_vblank_count); #endif