diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c index ddd7233bbac7..5580d3420c3a 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 1618e2294a16..e23843f4d877 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 b62c1710cab6..064ebb347074 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 cb0f7747e3dc..4dcc8fba5792 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 5af3721851d6..8f1e51128b33 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 4f7b49a6dc50..42d954dc436d 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; } /**