Attachment 123012 Details for Bug 94980 – Block SIGIO when we are trying to flip

[patch] Block SIGIO when we are trying to flip

0001-sna-Block-SIGIO-when-we-are-trying-to-flip.patch (text/plain), 3.60 KB, created by Chris Wilson on 2016-04-17 18:02:14 UTC

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Creator: Chris Wilson

Created: 2016-04-17 18:02:14 UTC

Size: 3.60 KB

patch

obsolete

>From 680ae24ea9ae050a126d7e31054f04a6182c2aa4 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Sun, 17 Apr 2016 18:58:09 +0100
>Subject: [PATCH] sna: Block SIGIO when we are trying to flip
>
>Temporarily stopping the pointer whilst we try to queue the flip should
>help keep the output latency down.
>
>Reported-by: Rafael Ristovski <rafael.ristovski@gmail.com>
>References: https://bugs.freedesktop.org/show_bug.cgi?id=94980
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> src/sna/sna_display.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
>diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
>index 3b5ae87..80b658a 100644
>--- a/src/sna/sna_display.c
>+++ b/src/sna/sna_display.c
>@@ -6438,6 +6438,7 @@ sna_page_flip(struct sna *sna,
> 	xf86CrtcConfigPtr config = XF86_CRTC_CONFIG_PTR(sna->scrn);
> 	const int width = sna->scrn->virtualX;
> 	const int height = sna->scrn->virtualY;
>+	int sigio;
> 	int count = 0;
> 	int i;
> 
>@@ -6455,6 +6456,7 @@ sna_page_flip(struct sna *sna,
> 
> 	kgem_bo_submit(&sna->kgem, bo);
> 
>+	sigio = sigio_block();
> 	for (i = 0; i < sna->mode.num_real_crtc; i++) {
> 		struct sna_crtc *crtc = config->crtc[i]->driver_private;
> 		struct drm_mode_crtc_page_flip arg;
>@@ -6478,7 +6480,7 @@ sna_page_flip(struct sna *sna,
> 		arg.fb_id = get_fb(sna, bo, width, height);
> 		if (arg.fb_id == 0) {
> 			assert(count == 0);
>-			return 0;
>+			break;
> 		}
> 
> 		fixup = 0;
>@@ -6551,7 +6553,7 @@ retry_flip:
> 					goto fixup_flip;
> 
> 				if (count == 0)
>-					return 0;
>+					break;
> 
> 				DBG(("%s: throttling on busy flip / waiting for kernel to catch up\n", __FUNCTION__));
> 				drmIoctl(sna->kgem.fd, DRM_IOCTL_I915_GEM_THROTTLE, 0);
>@@ -6572,7 +6574,8 @@ error:
> 				sna_mode_restore(sna);
> 
> 			sna->flags &= ~(data ? SNA_HAS_FLIP : SNA_HAS_ASYNC_FLIP);
>-			return 0;
>+			count = 0;
>+			break;
> 		}
> 
> 		if (data) {
>@@ -6593,6 +6596,7 @@ error:
> next_crtc:
> 		count++;
> 	}
>+	sigio_unblock(sigio);
> 
> 	DBG(("%s: page flipped %d crtcs\n", __FUNCTION__, count));
> 	return count;
>@@ -8741,6 +8745,7 @@ void sna_mode_redisplay(struct sna *sna)
> 		xf86CrtcPtr crtc = config->crtc[i];
> 		struct sna_crtc *sna_crtc = to_sna_crtc(crtc);
> 		RegionRec damage;
>+		int sigio;
> 
> 		assert(sna_crtc != NULL);
> 		DBG(("%s: crtc[%d] transformed? %d\n",
>@@ -8762,6 +8767,7 @@ void sna_mode_redisplay(struct sna *sna)
> 		     region_num_rects(&damage),
> 		     damage.extents.x1, damage.extents.y1,
> 		     damage.extents.x2, damage.extents.y2));
>+		sigio = sigio_block();
> 		if (!box_empty(&damage.extents)) {
> 			if (sna->flags & SNA_TEAR_FREE) {
> 				struct drm_mode_crtc_page_flip arg;
>@@ -8861,6 +8867,7 @@ disable1:
> 			}
> 		}
> 		RegionUninit(&damage);
>+		sigio_unblock(sigio);
> 
> 		if (sna_crtc->slave_damage)
> 			DamageEmpty(sna_crtc->slave_damage);
>@@ -8871,6 +8878,7 @@ disable1:
> 		struct kgem_bo *old = sna->mode.shadow;
> 		struct drm_mode_crtc_page_flip arg;
> 		uint32_t fb = 0;
>+		int sigio;
> 
> 		DBG(("%s: flipping TearFree outputs, current scanout handle=%d [active?=%d], new handle=%d [active=%d]\n",
> 		     __FUNCTION__, old->handle, old->active_scanout, new->handle, new->active_scanout));
>@@ -8883,6 +8891,7 @@ disable1:
> 
> 		kgem_bo_submit(&sna->kgem, new);
> 
>+		sigio = sigio_block();
> 		for (i = 0; i < sna->mode.num_real_crtc; i++) {
> 			struct sna_crtc *crtc = config->crtc[i]->driver_private;
> 			struct kgem_bo *flip_bo;
>@@ -8930,6 +8939,7 @@ fixup_shadow:
> 						}
> 					}
> 
>+					sigio_unblock(sigio);
> 					return;
> 				}
> 
>@@ -9021,6 +9031,7 @@ fixup_flip:
> 				}
> 			}
> 		}
>+		sigio_unblock(sigio);
> 
> 		DBG(("%s: flipped %d outputs, shadow active? %d\n",
> 		     __FUNCTION__,
>-- 
>2.8.0.rc3
>

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