From d7b9935a347ae954be907ea3d5eb4564ff124c53 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 20 Jan 2011 13:19:55 -0800 Subject: [PATCH] i915: Fix i915 suspend delay During system suspend, the "wait for ring buffer to empty" loop would always time out after three seconds, because the faster cached ring buffer head read would always return zero. Force the slow-and-careful PIO read on all but the first iterations of the loop to fix it. This also removes the unused (and useless) 'actual_head' variable that tried to approximate doing this, but did it incorrectly. Cc: Chris Wilson Cc: Rafael J. Wysocki Cc: Jesse Barnes Cc: Dave Airlie Cc: DRI mailing list Signed-off-by: Linus Torvalds --- drivers/gpu/drm/i915/intel_ringbuffer.c | 5 +++-- drivers/gpu/drm/i915/intel_ringbuffer.h | 1 - 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 03e33707..f6b9baa 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -928,6 +928,7 @@ static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring) int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n) { + int reread = 0; struct drm_device *dev = ring->dev; struct drm_i915_private *dev_priv = dev->dev_private; unsigned long end; @@ -940,9 +941,8 @@ int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n) * fallback to the slow and accurate path. */ head = intel_read_status_page(ring, 4); - if (head < ring->actual_head) + if (reread) head = I915_READ_HEAD(ring); - ring->actual_head = head; ring->head = head & HEAD_ADDR; ring->space = ring->head - (ring->tail + 8); if (ring->space < 0) @@ -961,6 +961,7 @@ int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n) msleep(1); if (atomic_read(&dev_priv->mm.wedged)) return -EAGAIN; + reread = 1; } while (!time_after(jiffies, end)); trace_i915_ring_wait_end (dev); return -EBUSY; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index be9087e..5b0abfa 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -47,7 +47,6 @@ struct intel_ring_buffer { struct drm_device *dev; struct drm_i915_gem_object *obj; - u32 actual_head; u32 head; u32 tail; int space; -- 2.7.4