Attachment 34686 Details for Bug 27040 – avoid queuing flips while flip is pending

[patch] avoid queuing flips while flip is pending

0003-drm-i915-don-t-queue-flips-during-a-flip-pending-eve.patch (text/plain), 1.70 KB, created by Jesse Barnes on 2010-04-05 14:08:38 UTC

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Creator: Jesse Barnes

Created: 2010-04-05 14:08:38 UTC

Size: 1.70 KB

patch

obsolete

>From a8ddc8b3743abb72b6c7e26ce75ae98d93d92133 Mon Sep 17 00:00:00 2001
>From: Jesse Barnes <jbarnes@virtuousgeek.org>
>Date: Mon, 5 Apr 2010 14:03:51 -0700
>Subject: [PATCH 3/3] drm/i915: don't queue flips during a flip pending event
>
>Hardware will set the flip pending ISR bit as soon as it receives the
>flip instruction, and (supposedly) clear it once the flip completes
>(e.g. at the next vblank).  If we try to send down a flip instruction
>while the ISR bit is set, the hardware can become very confused, and we
>may never receive the corresponding flip pending interrupt, effectively
>hanging the chip.
>
>Fixes fdo bug #27040.
>
>Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
>---
> drivers/gpu/drm/i915/intel_display.c |   10 ++++++++++
> 1 files changed, 10 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>index 6f5e7f5..24853e1 100644
>--- a/drivers/gpu/drm/i915/intel_display.c
>+++ b/drivers/gpu/drm/i915/intel_display.c
>@@ -4235,6 +4235,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
> 	unsigned long flags;
> 	int pipesrc_reg = (intel_crtc->pipe == 0) ? PIPEASRC : PIPEBSRC;
> 	int ret, pipesrc;
>+	u32 flip_mask;
> 	RING_LOCALS;
> 
> 	work = kzalloc(sizeof *work, GFP_KERNEL);
>@@ -4285,6 +4286,15 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
> 	atomic_inc(&obj_priv->pending_flip);
> 	work->pending_flip_obj = obj;
> 
>+	if (intel_crtc->plane)
>+		flip_mask = I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
>+	else
>+		flip_mask = I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT;
>+
>+	/* Wait for any previous flip to finish */
>+	while (I915_READ(ISR) & flip_mask)
>+		;
>+
> 	BEGIN_LP_RING(4);
> 	if (IS_I965G(dev)) {
> 		OUT_RING(MI_DISPLAY_FLIP |
>-- 
>1.6.6.1
>

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Attachments on bug 27040: 33985 | 33986 | 34686 | 34758 | 35996

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