[PATCH 3/3] kms/i915: Add support for precise vblank timestamping.
Mario Kleiner
mario.kleiner at tuebingen.mpg.de
Sun Oct 24 13:02:52 PDT 2010
This patch adds new functions for use by the drm core:
.get_vblank_timestamp() provides a precise timestamp
for the end of the most recent (or current) vblank
interval of a given crtc, as needed for the DRI2
implementation of the OML_sync_control extension.
It is a thin wrapper around the drm function
drm_calc_vbltimestamp_from_scanoutpos() which does
almost all the work.
.get_scanout_position() provides the current horizontal
and vertical video scanout position and "in vblank"
status of a given crtc, as needed by the drm for use by
drm_calc_vbltimestamp_from_scanoutpos().
The patch modifies the pageflip completion routine
to use these precise vblank timestamps as the timestamps
for pageflip completion events.
This code has been only tested on a HP-Mini Netbook with
Atom processor and Intel 945GME gpu. The codepath for
(IS_G4X(dev) || IS_IRONLAKE(dev) || IS_GEN6(dev)) gpu's
has not been tested so far due to lack of hardware.
Signed-off-by: Mario Kleiner <mario.kleiner at tuebingen.mpg.de>
---
drivers/gpu/drm/i915/i915_drv.c | 2 +
drivers/gpu/drm/i915/i915_drv.h | 7 +++
drivers/gpu/drm/i915/i915_irq.c | 92 ++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_display.c | 31 +++++++++---
drivers/gpu/drm/i915/intel_drv.h | 1 +
5 files changed, 126 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index c3decb2..4d8184a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -603,6 +603,8 @@ static struct drm_driver driver = {
.device_is_agp = i915_driver_device_is_agp,
.enable_vblank = i915_enable_vblank,
.disable_vblank = i915_disable_vblank,
+ .get_vblank_timestamp = i915_get_vblank_timestamp,
+ .get_scanout_position = i915_get_crtc_scanoutpos,
.irq_preinstall = i915_driver_irq_preinstall,
.irq_postinstall = i915_driver_irq_postinstall,
.irq_uninstall = i915_driver_irq_uninstall,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 73ad8bf..276fbdb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -948,6 +948,13 @@ void
i915_disable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask);
void intel_enable_asle (struct drm_device *dev);
+int i915_get_vblank_timestamp(struct drm_device *dev, int crtc,
+ int *max_error,
+ struct timeval *vblank_time,
+ unsigned flags);
+
+int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
+ int *vpos, int *hpos);
#ifdef CONFIG_DEBUG_FS
extern void i915_destroy_error_state(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 64c07c2..c9c8d4a 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -243,6 +243,98 @@ u32 gm45_get_vblank_counter(struct drm_device *dev, int pipe)
return I915_READ(reg);
}
+int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
+ int *vpos, int *hpos)
+{
+ drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+ int reg;
+ u32 vbl = 0, position = 0;
+ int vbl_start, vbl_end, htotal, vtotal;
+ bool in_vbl = true;
+ int ret = 0;
+
+ if (!i915_pipe_enabled(dev, pipe)) {
+ DRM_DEBUG_DRIVER("trying to get scanoutpos for disabled "
+ "pipe %d\n", pipe);
+ return 0;
+ }
+
+ /* Get vtotal. */
+ reg = pipe ? VTOTAL_B : VTOTAL_A;
+ vtotal = 1 + ((I915_READ(reg) >> 16) & 0x1fff);
+
+ if (IS_G4X(dev) || IS_IRONLAKE(dev) || IS_GEN6(dev)) {
+ /* No obvious pixelcount register. Only query vertical
+ * scanout position from Display scan line register.
+ */
+ reg = pipe ? PIPEBDSL : PIPEADSL;
+ position = I915_READ(reg);
+
+ /* Decode into vertical scanout position. Don't have
+ * horizontal scanout position.
+ */
+ *vpos = position & 0x1fff;
+ *hpos = 0;
+ } else {
+ /* Have access to pixelcount since start of frame.
+ * We can split this into vertical and horizontal
+ * scanout position.
+ */
+ reg = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
+ position = (I915_READ(reg) & PIPE_PIXEL_MASK) >> PIPE_PIXEL_SHIFT;
+
+ reg = pipe ? HTOTAL_B : HTOTAL_A;
+ htotal = 1 + ((I915_READ(reg) >> 16) & 0x1fff);
+ *vpos = position / htotal;
+ *hpos = position - (*vpos * htotal);
+ }
+
+ /* Query vblank area. */
+ reg = pipe ? VBLANK_B : VBLANK_A;
+ vbl = I915_READ(reg);
+
+ /* Test position against vblank region. */
+ vbl_start = vbl & 0x1fff;
+ vbl_end = (vbl >> 16) & 0x1fff;
+
+ if ((*vpos < vbl_start) || (*vpos > vbl_end))
+ in_vbl = false;
+
+ /* Inside "upper part" of vblank area? Apply corrective offset: */
+ if (in_vbl && (*vpos >= vbl_start))
+ *vpos = *vpos - vtotal;
+
+ /* Readouts valid? */
+ if (vbl > 0)
+ ret |= DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE;
+
+ /* In vblank? */
+ if (in_vbl)
+ ret |= DRM_SCANOUTPOS_INVBL;
+
+ return ret;
+}
+
+int i915_get_vblank_timestamp(struct drm_device *dev, int crtc,
+ int *max_error,
+ struct timeval *vblank_time,
+ unsigned flags)
+{
+ struct drm_crtc *drmcrtc;
+
+ if (crtc < 0 || crtc >= dev->num_crtcs) {
+ DRM_ERROR("Invalid crtc %d\n", crtc);
+ return -EINVAL;
+ }
+
+ /* Get drm_crtc to timestamp: */
+ drmcrtc = intel_get_crtc_for_pipe(dev, crtc);
+
+ /* Helper routine in DRM core does all the work: */
+ return drm_calc_vbltimestamp_from_scanoutpos(dev, crtc, max_error,
+ vblank_time, flags, drmcrtc);
+}
+
/*
* Handle hotplug events outside the interrupt handler proper.
*/
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 96d08a9..47853e5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4591,7 +4591,7 @@ void intel_release_load_detect_pipe(struct intel_encoder *intel_encoder,
}
/* Returns the clock of the currently programmed mode of the given pipe. */
-static int intel_crtc_clock_get(struct drm_device *dev, struct drm_crtc *crtc)
+int intel_crtc_clock_get(struct drm_device *dev, struct drm_crtc *crtc)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -4955,7 +4955,8 @@ static void intel_unpin_work_fn(struct work_struct *__work)
}
static void do_intel_finish_page_flip(struct drm_device *dev,
- struct drm_crtc *crtc)
+ struct drm_crtc *crtc,
+ int called_before_vblirq)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -4977,19 +4978,33 @@ static void do_intel_finish_page_flip(struct drm_device *dev,
}
intel_crtc->unpin_work = NULL;
- drm_vblank_put(dev, intel_crtc->pipe);
if (work->event) {
e = work->event;
- do_gettimeofday(&now);
- e->event.sequence = drm_vblank_count(dev, intel_crtc->pipe);
+ e->event.sequence = drm_vblank_count_and_time(dev, intel_crtc->pipe, &now);
+
+ /* Called before vblank count and timestamps have
+ * been updated for the vblank interval of flip
+ * completion? Need to increment vblank count and
+ * add one videorefresh duration to returned timestamp
+ * to account for this.
+ */
+ if (called_before_vblirq) {
+ e->event.sequence++;
+ now = ns_to_timeval(timeval_to_ns(&now) +
+ crtc->framedur_ns);
+ }
+
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
+
list_add_tail(&e->base.link,
&e->base.file_priv->event_list);
wake_up_interruptible(&e->base.file_priv->event_wait);
}
+ drm_vblank_put(dev, intel_crtc->pipe);
+
spin_unlock_irqrestore(&dev->event_lock, flags);
obj_priv = to_intel_bo(work->pending_flip_obj);
@@ -5008,7 +5023,8 @@ void intel_finish_page_flip(struct drm_device *dev, int pipe)
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
- do_intel_finish_page_flip(dev, crtc);
+ /* Called after drm_handle_vblank has run for finish vblank. */
+ do_intel_finish_page_flip(dev, crtc, 0);
}
void intel_finish_page_flip_plane(struct drm_device *dev, int plane)
@@ -5016,7 +5032,8 @@ void intel_finish_page_flip_plane(struct drm_device *dev, int plane)
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_crtc *crtc = dev_priv->plane_to_crtc_mapping[plane];
- do_intel_finish_page_flip(dev, crtc);
+ /* Called before drm_handle_vblank has run for finish vblank. */
+ do_intel_finish_page_flip(dev, crtc, 1);
}
void intel_prepare_page_flip(struct drm_device *dev, int plane)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 40e99bf..1e19e3e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -240,6 +240,7 @@ extern struct drm_encoder *intel_best_encoder(struct drm_connector *connector);
extern struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
struct drm_crtc *crtc);
+extern int intel_crtc_clock_get(struct drm_device *dev, struct drm_crtc *crtc);
int intel_get_pipe_from_crtc_id(struct drm_device *dev, void *data,
struct drm_file *file_priv);
extern void intel_wait_for_vblank(struct drm_device *dev, int pipe);
--
1.7.1
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