From: =?utf-8?q?Michel_D=C3=A4nzer?= Date: Mon, 11 Dec 2006 07:32:27 +0000 (+1100) Subject: i915_vblank_tasklet: Try harder to avoid tearing. X-Git-Tag: v2.6.20-rc2~85^2~6 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3188a24c256bae0ed93d81d82db1f1bb6060d727;p=linux-2.6 i915_vblank_tasklet: Try harder to avoid tearing. Previously, if there were several buffer swaps scheduled for the same vertical blank, all but the first blit emitted stood a chance of exhibiting tearing. In order to avoid this, split the blits along slices of each output top to bottom. Signed-off-by: Dave Airlie --- diff --git a/drivers/char/drm/i915_irq.c b/drivers/char/drm/i915_irq.c index e5463b111f..e2c4b3a41b 100644 --- a/drivers/char/drm/i915_irq.c +++ b/drivers/char/drm/i915_irq.c @@ -46,88 +46,167 @@ static void i915_vblank_tasklet(drm_device_t *dev) { drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private; unsigned long irqflags; - struct list_head *list, *tmp; + struct list_head *list, *tmp, hits, *hit; + int nhits, nrects, slice[2], upper[2], lower[2], i; + unsigned counter[2] = { atomic_read(&dev->vbl_received), + atomic_read(&dev->vbl_received2) }; + drm_drawable_info_t *drw; + drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv; + u32 cpp = dev_priv->cpp; + u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD | + XY_SRC_COPY_BLT_WRITE_ALPHA | + XY_SRC_COPY_BLT_WRITE_RGB) + : XY_SRC_COPY_BLT_CMD; + u32 pitchropcpp = (sarea_priv->pitch * cpp) | (0xcc << 16) | + (cpp << 23) | (1 << 24); + RING_LOCALS; DRM_DEBUG("\n"); + INIT_LIST_HEAD(&hits); + + nhits = nrects = 0; + spin_lock_irqsave(&dev_priv->swaps_lock, irqflags); + /* Find buffer swaps scheduled for this vertical blank */ list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) { drm_i915_vbl_swap_t *vbl_swap = list_entry(list, drm_i915_vbl_swap_t, head); - atomic_t *counter = vbl_swap->pipe ? &dev->vbl_received2 : - &dev->vbl_received; - - if ((atomic_read(counter) - vbl_swap->sequence) <= (1<<23)) { - drm_drawable_info_t *drw; - - spin_unlock(&dev_priv->swaps_lock); - - spin_lock(&dev->drw_lock); - - drw = drm_get_drawable_info(dev, vbl_swap->drw_id); - - if (drw) { - int i, num_rects = drw->num_rects; - drm_clip_rect_t *rect = drw->rects; - drm_i915_sarea_t *sarea_priv = - dev_priv->sarea_priv; - u32 cpp = dev_priv->cpp; - u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD | - XY_SRC_COPY_BLT_WRITE_ALPHA | - XY_SRC_COPY_BLT_WRITE_RGB) - : XY_SRC_COPY_BLT_CMD; - u32 pitchropcpp = (sarea_priv->pitch * cpp) | - (0xcc << 16) | (cpp << 23) | - (1 << 24); - RING_LOCALS; - - i915_kernel_lost_context(dev); - - BEGIN_LP_RING(6); - - OUT_RING(GFX_OP_DRAWRECT_INFO); - OUT_RING(0); - OUT_RING(0); - OUT_RING(sarea_priv->width | - sarea_priv->height << 16); - OUT_RING(sarea_priv->width | - sarea_priv->height << 16); - OUT_RING(0); - ADVANCE_LP_RING(); + if ((counter[vbl_swap->pipe] - vbl_swap->sequence) > (1<<23)) + continue; + + list_del(list); + dev_priv->swaps_pending--; - sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT; + spin_unlock(&dev_priv->swaps_lock); + spin_lock(&dev->drw_lock); - for (i = 0; i < num_rects; i++, rect++) { - BEGIN_LP_RING(8); + drw = drm_get_drawable_info(dev, vbl_swap->drw_id); + + if (!drw) { + spin_unlock(&dev->drw_lock); + drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER); + spin_lock(&dev_priv->swaps_lock); + continue; + } - OUT_RING(cmd); - OUT_RING(pitchropcpp); - OUT_RING((rect->y1 << 16) | rect->x1); - OUT_RING((rect->y2 << 16) | rect->x2); - OUT_RING(sarea_priv->front_offset); - OUT_RING((rect->y1 << 16) | rect->x1); - OUT_RING(pitchropcpp & 0xffff); - OUT_RING(sarea_priv->back_offset); + list_for_each(hit, &hits) { + drm_i915_vbl_swap_t *swap_cmp = + list_entry(hit, drm_i915_vbl_swap_t, head); + drm_drawable_info_t *drw_cmp = + drm_get_drawable_info(dev, swap_cmp->drw_id); - ADVANCE_LP_RING(); - } + if (drw_cmp && + drw_cmp->rects[0].y1 > drw->rects[0].y1) { + list_add_tail(list, hit); + break; } + } - spin_unlock(&dev->drw_lock); + spin_unlock(&dev->drw_lock); - spin_lock(&dev_priv->swaps_lock); + /* List of hits was empty, or we reached the end of it */ + if (hit == &hits) + list_add_tail(list, hits.prev); - list_del(list); + nhits++; - drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER); + spin_lock(&dev_priv->swaps_lock); + } + + if (nhits == 0) { + spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags); + return; + } + + spin_unlock(&dev_priv->swaps_lock); - dev_priv->swaps_pending--; + i915_kernel_lost_context(dev); + + BEGIN_LP_RING(6); + + OUT_RING(GFX_OP_DRAWRECT_INFO); + OUT_RING(0); + OUT_RING(0); + OUT_RING(sarea_priv->width | sarea_priv->height << 16); + OUT_RING(sarea_priv->width | sarea_priv->height << 16); + OUT_RING(0); + + ADVANCE_LP_RING(); + + sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT; + + upper[0] = upper[1] = 0; + slice[0] = max(sarea_priv->pipeA_h / nhits, 1); + slice[1] = max(sarea_priv->pipeB_h / nhits, 1); + lower[0] = sarea_priv->pipeA_y + slice[0]; + lower[1] = sarea_priv->pipeB_y + slice[0]; + + spin_lock(&dev->drw_lock); + + /* Emit blits for buffer swaps, partitioning both outputs into as many + * slices as there are buffer swaps scheduled in order to avoid tearing + * (based on the assumption that a single buffer swap would always + * complete before scanout starts). + */ + for (i = 0; i++ < nhits; + upper[0] = lower[0], lower[0] += slice[0], + upper[1] = lower[1], lower[1] += slice[1]) { + if (i == nhits) + lower[0] = lower[1] = sarea_priv->height; + + list_for_each(hit, &hits) { + drm_i915_vbl_swap_t *swap_hit = + list_entry(hit, drm_i915_vbl_swap_t, head); + drm_clip_rect_t *rect; + int num_rects, pipe; + unsigned short top, bottom; + + drw = drm_get_drawable_info(dev, swap_hit->drw_id); + + if (!drw) + continue; + + rect = drw->rects; + pipe = swap_hit->pipe; + top = upper[pipe]; + bottom = lower[pipe]; + + for (num_rects = drw->num_rects; num_rects--; rect++) { + int y1 = max(rect->y1, top); + int y2 = min(rect->y2, bottom); + + if (y1 >= y2) + continue; + + BEGIN_LP_RING(8); + + OUT_RING(cmd); + OUT_RING(pitchropcpp); + OUT_RING((y1 << 16) | rect->x1); + OUT_RING((y2 << 16) | rect->x2); + OUT_RING(sarea_priv->front_offset); + OUT_RING((y1 << 16) | rect->x1); + OUT_RING(pitchropcpp & 0xffff); + OUT_RING(sarea_priv->back_offset); + + ADVANCE_LP_RING(); + } } } - spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags); + spin_unlock_irqrestore(&dev->drw_lock, irqflags); + + list_for_each_safe(hit, tmp, &hits) { + drm_i915_vbl_swap_t *swap_hit = + list_entry(hit, drm_i915_vbl_swap_t, head); + + list_del(hit); + + drm_free(swap_hit, sizeof(*swap_hit), DRM_MEM_DRIVER); + } } irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)