From 08deebf98783d3de553eed2c9b6b8dcc7e168567 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 5 Nov 2010 08:56:38 +0000 Subject: [PATCH] drm/i915/ringbuffer: Use the HEAD auto-reporting mechanism My Sandybridge only reports 0 for the ring buffer registers, causing it to hang as soon as we exhaust the available ring. As a workaround, take advantage of our huge ring buffers and use the auto-reporting mechanism to update the status page with the HEAD location every 64 KiB. Cherry-picked from 6aa56062eaba67adfb247cded244fd877329588d. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31404 Tested-by: Zhao Jian Cc: stable@kernel.org Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/intel_ringbuffer.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 7c1f3ff2f788..b83306f9244b 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -177,7 +177,7 @@ static int init_ring_common(struct drm_device *dev, I915_WRITE_CTL(ring, ((ring->gem_object->size - PAGE_SIZE) & RING_NR_PAGES) - | RING_NO_REPORT | RING_VALID); + | RING_REPORT_64K | RING_VALID); head = I915_READ_HEAD(ring) & HEAD_ADDR; /* If the head is still not zero, the ring is dead */ @@ -692,6 +692,17 @@ int intel_wait_ring_buffer(struct drm_device *dev, { unsigned long end; 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;