Replace the handcrafter loop when checking for fifo slots with atomic wait for. This brings this wait in line with the other waits on register access. We also get a readable timeout constraint, so make it to fail after 10ms. Chris suggested that we should fail silently as the fifo debug handler, now attached to unclaimed mmio handling, will take care of the possible errors at later stage. Note that the decision to wait was changed so that we avoid allocating the first reserved entry. Nor do we reduce the count if we fail the wait, removing the possiblity to wrap the count if the hw fifo returned zero. References: https://bugs.freedesktop.org/show_bug.cgi?id=100247 Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_uncore.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index a129a73..df744a8 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -29,6 +29,7 @@ #include <linux/pm_runtime.h> #define FORCEWAKE_ACK_TIMEOUT_MS 50 +#define GT_FIFO_TIMEOUT_MS 10 #define __raw_posting_read(dev_priv__, reg__) (void)__raw_i915_read32((dev_priv__), (reg__)) @@ -181,28 +182,27 @@ static inline u32 fifo_free_entries(struct drm_i915_private *dev_priv) static int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv) { - int ret = 0; + u32 n; /* On VLV, FIFO will be shared by both SW and HW. * So, we need to read the FREE_ENTRIES everytime */ if (IS_VALLEYVIEW(dev_priv)) - dev_priv->uncore.fifo_count = fifo_free_entries(dev_priv); - - if (dev_priv->uncore.fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES) { - int loop = 500; - u32 fifo = fifo_free_entries(dev_priv); - - while (fifo <= GT_FIFO_NUM_RESERVED_ENTRIES && loop--) { - udelay(10); - fifo = fifo_free_entries(dev_priv); + n = fifo_free_entries(dev_priv); + else + n = dev_priv->uncore.fifo_count; + + if (n <= GT_FIFO_NUM_RESERVED_ENTRIES) { + if (wait_for_atomic((n = fifo_free_entries(dev_priv)) > + GT_FIFO_NUM_RESERVED_ENTRIES, + GT_FIFO_TIMEOUT_MS)) { + DRM_DEBUG("GT_FIFO timeout, entries: %u, unclaimed: %d\n", n, + intel_uncore_unclaimed_mmio(dev_priv)); + return -EBUSY; } - if (WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES)) - ++ret; - dev_priv->uncore.fifo_count = fifo; } - dev_priv->uncore.fifo_count--; - return ret; + dev_priv->uncore.fifo_count = n - 1; + return 0; } static enum hrtimer_restart -- 2.7.4 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
