diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index ddd7233bbac75607cd855c6570200fe714c83b0d..5580d3420c3a368815364d8eccce3e1421ce6a12 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -73,6 +73,8 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
struct drm_crtc *crtc = &amdgpuCrtc->base;
unsigned long flags;
unsigned i;
+ int vpos, hpos, stat, min_udelay;
+ struct drm_vblank_crtc *vblank = &crtc->dev->vblank[work->crtc_id];
amdgpu_flip_wait_fence(adev, &work->excl);
for (i = 0; i < work->shared_count; ++i)
@@ -81,6 +83,41 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
/* We borrow the event spin lock for protecting flip_status */
spin_lock_irqsave(&crtc->dev->event_lock, flags);
+ /* If this happens to execute within the "virtually extended" vblank
+ * interval before the start of the real vblank interval then it needs
+ * to delay programming the mmio flip until the real vblank is entered.
+ * This prevents completing a flip too early due to the way we fudge
+ * our vblank counter and vblank timestamps in order to work around the
+ * problem that the hw fires vblank interrupts before actual start of
+ * vblank (when line buffer refilling is done for a frame). It
+ * complements the fudging logic in amdgpu_get_crtc_scanoutpos() for
+ * timestamping and amdgpu_get_vblank_counter_kms() for vblank counts.
+ *
+ * In practice this won't execute very often unless on very fast
+ * machines because the time window for this to happen is very small.
+ */
+ for (;;) {
+ /* GET_DISTANCE_TO_VBLANKSTART returns distance to real vblank
+ * start in hpos, and to the "fudged earlier" vblank start in
+ * vpos.
+ */
+ stat = amdgpu_get_crtc_scanoutpos(adev->ddev, work->crtc_id,
+ GET_DISTANCE_TO_VBLANKSTART,
+ &vpos, &hpos, NULL, NULL,
+ &crtc->hwmode);
+
+ if ((stat & (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE)) !=
+ (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE) ||
+ !(vpos >= 0 && hpos <= 0))
+ break;
+
+ /* Sleep at least until estimated real start of hw vblank */
+ spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
+ min_udelay = (-hpos + 1) * max(vblank->linedur_ns / 1000, 5);
+ usleep_range(min_udelay, 2 * min_udelay);
+ spin_lock_irqsave(&crtc->dev->event_lock, flags);
+ };
+
/* do the flip (mmio) */
adev->mode_info.funcs->page_flip(adev, work->crtc_id, work->base);
/* set the flip status */
@@ -712,6 +749,15 @@ bool amdgpu_crtc_scaling_mode_fixup(struct drm_crtc *crtc,
* \param dev Device to query.
* \param pipe Crtc to query.
* \param flags Flags from caller (DRM_CALLED_FROM_VBLIRQ or 0).
+ * For driver internal use only also supports these flags:
+ *
+ * USE_REAL_VBLANKSTART to use the real start of vblank instead
+ * of a fudged earlier start of vblank.
+ *
+ * GET_DISTANCE_TO_VBLANKSTART to return distance to the
+ * fudged earlier start of vblank in *vpos and the distance
+ * to true start of vblank in *hpos.
+ *
* \param *vpos Location where vertical scanout position should be stored.
* \param *hpos Location where horizontal scanout position should go.
* \param *stime Target location for timestamp taken immediately before
@@ -776,10 +822,40 @@ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
vbl_end = 0;
}
+ /* Called from driver internal vblank counter query code? */
+ if (flags & GET_DISTANCE_TO_VBLANKSTART) {
+ /* Caller wants distance from real vbl_start in *hpos */
+ *hpos = *vpos - vbl_start;
+ }
+
+ /* Fudge vblank to start a few scanlines earlier to handle the
+ * problem that vblank irqs fire a few scanlines before start
+ * of vblank. Some driver internal callers need the true vblank
+ * start to be used and signal this via the USE_REAL_VBLANKSTART flag.
+ *
+ * The cause of the "early" vblank irq is that the irq is triggered
+ * by the line buffer logic when the line buffer read position enters
+ * the vblank, whereas our crtc scanout position naturally lags the
+ * line buffer read position.
+ */
+ if (!(flags & USE_REAL_VBLANKSTART))
+ vbl_start -= adev->mode_info.crtcs[pipe]->lb_vblank_lead_lines;
+
/* Test scanout position against vblank region. */
if ((*vpos < vbl_start) && (*vpos >= vbl_end))
in_vbl = false;
+ /* In vblank? */
+ if (in_vbl)
+ ret |= DRM_SCANOUTPOS_IN_VBLANK;
+
+ /* Called from driver internal vblank counter query code? */
+ if (flags & GET_DISTANCE_TO_VBLANKSTART) {
+ /* Caller wants distance from fudged earlier vbl_start */
+ *vpos -= vbl_start;
+ return ret;
+ }
+
/* Check if inside vblank area and apply corrective offsets:
* vpos will then be >=0 in video scanout area, but negative
* within vblank area, counting down the number of lines until
@@ -795,32 +871,6 @@ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
/* Correct for shifted end of vbl at vbl_end. */
*vpos = *vpos - vbl_end;
- /* In vblank? */
- if (in_vbl)
- ret |= DRM_SCANOUTPOS_IN_VBLANK;
-
- /* Is vpos outside nominal vblank area, but less than
- * 1/100 of a frame height away from start of vblank?
- * If so, assume this isn't a massively delayed vblank
- * interrupt, but a vblank interrupt that fired a few
- * microseconds before true start of vblank. Compensate
- * by adding a full frame duration to the final timestamp.
- * Happens, e.g., on ATI R500, R600.
- *
- * We only do this if DRM_CALLED_FROM_VBLIRQ.
- */
- if ((flags & DRM_CALLED_FROM_VBLIRQ) && !in_vbl) {
- vbl_start = mode->crtc_vdisplay;
- vtotal = mode->crtc_vtotal;
-
- if (vbl_start - *vpos < vtotal / 100) {
- *vpos -= vtotal;
-
- /* Signal this correction as "applied". */
- ret |= 0x8;
- }
- }
-
return ret;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 1618e2294a16056171458998ed65e62a83583774..e23843f4d877be7813a1574db0f855847f9aa591 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -611,13 +611,59 @@ void amdgpu_driver_preclose_kms(struct drm_device *dev,
u32 amdgpu_get_vblank_counter_kms(struct drm_device *dev, unsigned int pipe)
{
struct amdgpu_device *adev = dev->dev_private;
+ int vpos, hpos, stat;
+ u32 count;
if (pipe >= adev->mode_info.num_crtc) {
DRM_ERROR("Invalid crtc %u\n", pipe);
return -EINVAL;
}
- return amdgpu_display_vblank_get_counter(adev, pipe);
+ /* The hw increments its frame counter at start of vsync, not at start
+ * of vblank, as is required by DRM core vblank counter handling.
+ * Cook the hw count here to make it appear to the caller as if it
+ * incremented at start of vblank. We measure distance to start of
+ * vblank in vpos. vpos therefore will be >= 0 between start of vblank
+ * and start of vsync, so vpos >= 0 means to bump the hw frame counter
+ * result by 1 to give the proper appearance to caller.
+ */
+ if (adev->mode_info.crtcs[pipe]) {
+ /* Repeat readout if needed to provide stable result if
+ * we cross start of vsync during the queries.
+ */
+ do {
+ count = amdgpu_display_vblank_get_counter(adev, pipe);
+ /* Ask amdgpu_get_crtc_scanoutpos to return vpos as
+ * distance to start of vblank, instead of regular
+ * vertical scanout pos.
+ */
+ stat = amdgpu_get_crtc_scanoutpos(
+ dev, pipe, GET_DISTANCE_TO_VBLANKSTART,
+ &vpos, &hpos, NULL, NULL,
+ &adev->mode_info.crtcs[pipe]->base.hwmode);
+ } while (count != amdgpu_display_vblank_get_counter(adev, pipe));
+
+ if (((stat & (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE)) !=
+ (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE))) {
+ DRM_DEBUG_VBL("Query failed! stat %d\n", stat);
+ } else {
+ DRM_DEBUG_VBL("crtc %d: dist from vblank start %d\n",
+ pipe, vpos);
+
+ /* Bump counter if we are at >= leading edge of vblank,
+ * but before vsync where vpos would turn negative and
+ * the hw counter really increments.
+ */
+ if (vpos >= 0)
+ count++;
+ }
+ } else {
+ /* Fallback to use value as is. */
+ count = amdgpu_display_vblank_get_counter(adev, pipe);
+ DRM_DEBUG_VBL("NULL mode info! Returned count may be wrong.\n");
+ }
+
+ return count;
}
/**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
index b62c1710cab6b0fc00e33013ad741c97f9583ed2..064ebb3470748619e0b43ff7bfe2671a58c50bbd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -407,6 +407,7 @@ struct amdgpu_crtc {
u32 line_time;
u32 wm_low;
u32 wm_high;
+ u32 lb_vblank_lead_lines;
struct drm_display_mode hw_mode;
};
@@ -528,6 +529,10 @@ struct amdgpu_framebuffer {
#define ENCODER_MODE_IS_DP(em) (((em) == ATOM_ENCODER_MODE_DP) || \
((em) == ATOM_ENCODER_MODE_DP_MST))
+/* Driver internal use only flags of amdgpu_get_crtc_scanoutpos() */
+#define USE_REAL_VBLANKSTART (1 << 30)
+#define GET_DISTANCE_TO_VBLANKSTART (1 << 31)
+
void amdgpu_link_encoder_connector(struct drm_device *dev);
struct drm_connector *
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index cb0f7747e3dcac2dfa923d43fc0dd8574968d575..4dcc8fba579203297ece7849ab8a861ecbe33f10 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -1250,7 +1250,7 @@ static void dce_v10_0_program_watermarks(struct amdgpu_device *adev,
u32 pixel_period;
u32 line_time = 0;
u32 latency_watermark_a = 0, latency_watermark_b = 0;
- u32 tmp, wm_mask;
+ u32 tmp, wm_mask, lb_vblank_lead_lines = 0;
if (amdgpu_crtc->base.enabled && num_heads && mode) {
pixel_period = 1000000 / (u32)mode->clock;
@@ -1333,6 +1333,7 @@ static void dce_v10_0_program_watermarks(struct amdgpu_device *adev,
(adev->mode_info.disp_priority == 2)) {
DRM_DEBUG_KMS("force priority to high\n");
}
+ lb_vblank_lead_lines = DIV_ROUND_UP(lb_size, mode->crtc_hdisplay);
}
/* select wm A */
@@ -1357,6 +1358,8 @@ static void dce_v10_0_program_watermarks(struct amdgpu_device *adev,
amdgpu_crtc->line_time = line_time;
amdgpu_crtc->wm_high = latency_watermark_a;
amdgpu_crtc->wm_low = latency_watermark_b;
+ /* Save number of lines the linebuffer leads before the scanout */
+ amdgpu_crtc->lb_vblank_lead_lines = lb_vblank_lead_lines;
}
/**
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
index 5af3721851d67e99b521328babc38c811a7e2c09..8f1e51128b33882d5680731b9afb08fcf1b1023c 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -1238,7 +1238,7 @@ static void dce_v11_0_program_watermarks(struct amdgpu_device *adev,
u32 pixel_period;
u32 line_time = 0;
u32 latency_watermark_a = 0, latency_watermark_b = 0;
- u32 tmp, wm_mask;
+ u32 tmp, wm_mask, lb_vblank_lead_lines = 0;
if (amdgpu_crtc->base.enabled && num_heads && mode) {
pixel_period = 1000000 / (u32)mode->clock;
@@ -1321,6 +1321,7 @@ static void dce_v11_0_program_watermarks(struct amdgpu_device *adev,
(adev->mode_info.disp_priority == 2)) {
DRM_DEBUG_KMS("force priority to high\n");
}
+ lb_vblank_lead_lines = DIV_ROUND_UP(lb_size, mode->crtc_hdisplay);
}
/* select wm A */
@@ -1345,6 +1346,8 @@ static void dce_v11_0_program_watermarks(struct amdgpu_device *adev,
amdgpu_crtc->line_time = line_time;
amdgpu_crtc->wm_high = latency_watermark_a;
amdgpu_crtc->wm_low = latency_watermark_b;
+ /* Save number of lines the linebuffer leads before the scanout */
+ amdgpu_crtc->lb_vblank_lead_lines = lb_vblank_lead_lines;
}
/**
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 4f7b49a6dc500c431ba9aa52727232156f60bda1..42d954dc436d03206c48aafe7655966870dfc931 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -1193,7 +1193,7 @@ static void dce_v8_0_program_watermarks(struct amdgpu_device *adev,
u32 pixel_period;
u32 line_time = 0;
u32 latency_watermark_a = 0, latency_watermark_b = 0;
- u32 tmp, wm_mask;
+ u32 tmp, wm_mask, lb_vblank_lead_lines = 0;
if (amdgpu_crtc->base.enabled && num_heads && mode) {
pixel_period = 1000000 / (u32)mode->clock;
@@ -1276,6 +1276,7 @@ static void dce_v8_0_program_watermarks(struct amdgpu_device *adev,
(adev->mode_info.disp_priority == 2)) {
DRM_DEBUG_KMS("force priority to high\n");
}
+ lb_vblank_lead_lines = DIV_ROUND_UP(lb_size, mode->crtc_hdisplay);
}
/* select wm A */
@@ -1302,6 +1303,8 @@ static void dce_v8_0_program_watermarks(struct amdgpu_device *adev,
amdgpu_crtc->line_time = line_time;
amdgpu_crtc->wm_high = latency_watermark_a;
amdgpu_crtc->wm_low = latency_watermark_b;
+ /* Save number of lines the linebuffer leads before the scanout */
+ amdgpu_crtc->lb_vblank_lead_lines = lb_vblank_lead_lines;
}
/**