From 6fd0d56e3bc1abfb237b8824261b613e21e77bc8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sun, 5 Dec 2010 20:42:33 +0000 Subject: drm/i915/ringbuffer: Only print an error on the second attempt to reset head There's not much we can do here but hope for the best. However the first failure happens quite frequently and if often remedied by the second attempt to reset HEAD. So only print the error if that attempt also fails. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=19802 Reported-by: Thomas Meyer Signed-off-by: Chris Wilson Cc: stable@kernel.org --- drivers/gpu/drm/i915/intel_ringbuffer.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.c') diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index b83306f9244..89a65be8a3f 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -156,23 +156,25 @@ static int init_ring_common(struct drm_device *dev, /* G45 ring initialization fails to reset head to zero */ if (head != 0) { - DRM_ERROR("%s head not reset to zero " - "ctl %08x head %08x tail %08x start %08x\n", - ring->name, - I915_READ_CTL(ring), - I915_READ_HEAD(ring), - I915_READ_TAIL(ring), - I915_READ_START(ring)); + DRM_DEBUG_KMS("%s head not reset to zero " + "ctl %08x head %08x tail %08x start %08x\n", + ring->name, + I915_READ_CTL(ring), + I915_READ_HEAD(ring), + I915_READ_TAIL(ring), + I915_READ_START(ring)); I915_WRITE_HEAD(ring, 0); - DRM_ERROR("%s head forced to zero " - "ctl %08x head %08x tail %08x start %08x\n", - ring->name, - I915_READ_CTL(ring), - I915_READ_HEAD(ring), - I915_READ_TAIL(ring), - I915_READ_START(ring)); + if (I915_READ_HEAD(ring) & HEAD_ADDR) { + DRM_ERROR("failed to set %s head to zero " + "ctl %08x head %08x tail %08x start %08x\n", + ring->name, + I915_READ_CTL(ring), + I915_READ_HEAD(ring), + I915_READ_TAIL(ring), + I915_READ_START(ring)); + } } I915_WRITE_CTL(ring, -- cgit v1.2.3-70-g09d2 From 8c0a6bfef165ccdbf5d73afb9dd660107b0c98d5 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 9 Dec 2010 12:56:37 +0000 Subject: drm/i915/ringbuffer: Handle wrapping of the autoreported HEAD If the tail advances beyond the autoreport HEAD value, then we need to fallback to an uncached read of the HEAD register in order to ascertain the correct amount of remaining space in the ringbuffer. Reported-by: Fang, Xun Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32259 Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/intel_ringbuffer.c | 19 ++++++++----------- drivers/gpu/drm/i915/intel_ringbuffer.h | 5 +++-- 2 files changed, 11 insertions(+), 13 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.c') diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 89a65be8a3f..31cd7e33e82 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -696,20 +696,17 @@ int intel_wait_ring_buffer(struct drm_device *dev, drm_i915_private_t *dev_priv = dev->dev_private; u32 head; - head = intel_read_status_page(ring, 4); - if (head) { - ring->head = head & HEAD_ADDR; - ring->space = ring->head - (ring->tail + 8); - if (ring->space < 0) - ring->space += ring->size; - if (ring->space >= n) - return 0; - } - trace_i915_ring_wait_begin (dev); end = jiffies + 3 * HZ; do { - ring->head = I915_READ_HEAD(ring) & HEAD_ADDR; + /* If the reported head position has wrapped or hasn't advanced, + * fallback to the slow and accurate path. + */ + head = intel_read_status_page(ring, 4); + if (head < ring->actual_head) + 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) ring->space += ring->size; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 3126c268198..d2cd0f1efee 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -30,8 +30,9 @@ struct intel_ring_buffer { struct drm_device *dev; struct drm_gem_object *gem_object; - unsigned int head; - unsigned int tail; + u32 actual_head; + u32 head; + u32 tail; int space; struct intel_hw_status_page status_page; -- cgit v1.2.3-70-g09d2