The callback struct drm_driver.get_scanout_position() is deprecated in
favor of struct drm_crtc_helper_funcs.get_scanout_position().
i915 doesn't use CRTC helpers. The patch duplicates the caller
drm_calc_vbltimestamp_from_scanoutpos() for i915, such that the callback
function is not needed.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.c | 3 +-
drivers/gpu/drm/i915/i915_irq.c | 117 ++++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/i915_irq.h | 9 +--
3 files changed, 119 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f7385abdd74b..4a0a7fb85c53 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2769,8 +2769,7 @@ static struct drm_driver driver = {
.gem_prime_export = i915_gem_prime_export,
.gem_prime_import = i915_gem_prime_import,
- .get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos,
- .get_scanout_position = i915_get_crtc_scanoutpos,
+ .get_vblank_timestamp = i915_calc_vbltimestamp_from_scanoutpos,
.dumb_create = i915_gem_dumb_create,
.dumb_map_offset = i915_gem_dumb_mmap_offset,
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index afc6aad9bf8c..99d0c3b0feae 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -52,6 +52,11 @@
#include "i915_trace.h"
#include "intel_pm.h"
+/* Retry timestamp calculation up to 3 times to satisfy
+ * drm_timestamp_precision before giving up.
+ */
+#define I915_TIMESTAMP_MAXRETRIES 3
+
/**
* DOC: interrupt handling
*
@@ -762,10 +767,11 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
return (position + crtc->scanline_offset) % vtotal;
}
-bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index,
- bool in_vblank_irq, int *vpos, int *hpos,
- ktime_t *stime, ktime_t *etime,
- const struct drm_display_mode *mode)
+static bool i915_get_crtc_scanoutpos(struct drm_device *dev,
+ unsigned int index, bool in_vblank_irq,
+ int *vpos, int *hpos,
+ ktime_t *stime, ktime_t *etime,
+ const struct drm_display_mode *mode)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct intel_crtc *crtc = to_intel_crtc(drm_crtc_from_index(dev, index));
@@ -879,6 +885,109 @@ bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index,
return true;
}
+bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
+ unsigned int pipe,
+ int *max_error,
+ ktime_t *vblank_time,
+ bool in_vblank_irq)
+{
+ struct timespec64 ts_etime, ts_vblank_time;
+ ktime_t stime, etime;
+ bool vbl_status;
+ struct drm_crtc *crtc;
+ const struct drm_display_mode *mode;
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ int vpos, hpos, i;
+ int delta_ns, duration_ns;
+
+ crtc = drm_crtc_from_index(dev, pipe);
+
+ if (pipe >= dev->num_crtcs || !crtc) {
+ DRM_ERROR("Invalid crtc %u\n", pipe);
+ return false;
+ }
+
+ if (drm_drv_uses_atomic_modeset(dev))
+ mode = &vblank->hwmode;
+ else
+ mode = &crtc->hwmode;
+
+ /* If mode timing undefined, just return as no-op:
+ * Happens during initial modesetting of a crtc.
+ */
+ if (mode->crtc_clock == 0) {
+ DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
+ WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev));
+
+ return false;
+ }
+
+ /* Get current scanout position with system timestamp.
+ * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
+ * if single query takes longer than max_error nanoseconds.
+ *
+ * This guarantees a tight bound on maximum error if
+ * code gets preempted or delayed for some reason.
+ */
+ for (i = 0; i < I915_TIMESTAMP_MAXRETRIES; i++) {
+ /*
+ * Get vertical and horizontal scanout position vpos, hpos,
+ * and bounding timestamps stime, etime, pre/post query.
+ */
+ vbl_status = i915_get_crtc_scanoutpos(dev, pipe, in_vblank_irq,
+ &vpos, &hpos, &stime,
+ &etime, mode);
+ /* Return as no-op if scanout query unsupported or failed. */
+ if (!vbl_status) {
+ DRM_DEBUG("crtc %u : scanoutpos query failed.\n",
+ pipe);
+ return false;
+ }
+
+ /* Compute uncertainty in timestamp of scanout position query. */
+ duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
+
+ /* Accept result with < max_error nsecs timing uncertainty. */
+ if (duration_ns <= *max_error)
+ break;
+ }
+
+ /* Noisy system timing? */
+ if (i == I915_TIMESTAMP_MAXRETRIES) {
+ DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
+ pipe, duration_ns/1000, *max_error/1000, i);
+ }
+
+ /* Return upper bound of timestamp precision error. */
+ *max_error = duration_ns;
+
+ /* Convert scanout position into elapsed time at raw_time query
+ * since start of scanout at first display scanline. delta_ns
+ * can be negative if start of scanout hasn't happened yet.
+ */
+ delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
+ mode->crtc_clock);
+
+ /* Subtract time delta from raw timestamp to get final
+ * vblank_time timestamp for end of vblank.
+ */
+ *vblank_time = ktime_sub_ns(etime, delta_ns);
+
+ if (!drm_debug_enabled(DRM_UT_VBL))
+ return true;
+
+ ts_etime = ktime_to_timespec64(etime);
+ ts_vblank_time = ktime_to_timespec64(*vblank_time);
+
+ DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n",
+ pipe, hpos, vpos,
+ (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000,
+ (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000,
+ duration_ns / 1000, i);
+
+ return true;
+}
+
int intel_get_crtc_scanline(struct intel_crtc *crtc)
{
struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
diff --git a/drivers/gpu/drm/i915/i915_irq.h b/drivers/gpu/drm/i915/i915_irq.h
index 812c47a9c2d6..5f7b133ce721 100644
--- a/drivers/gpu/drm/i915/i915_irq.h
+++ b/drivers/gpu/drm/i915/i915_irq.h
@@ -101,10 +101,11 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
u8 pipe_mask);
-bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
- bool in_vblank_irq, int *vpos, int *hpos,
- ktime_t *stime, ktime_t *etime,
- const struct drm_display_mode *mode);
+bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
+ unsigned int pipe,
+ int *max_error,
+ ktime_t *vblank_time,
+ bool in_vblank_irq);
u32 i915_get_vblank_counter(struct drm_crtc *crtc);
u32 g4x_get_vblank_counter(struct drm_crtc *crtc);
--
2.24.1
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