On Tue, Feb 07, 2012 at 04:21:50PM +0100, Ben Widawsky wrote:
> If we don't have a sufficient number of free entries in the FIFO, we
> proceed to do a write anyway. With this check we should have a clue if
> that write actually failed or not.
>
> After some discussion with Daniel Vetter regarding his original
> complaint, we agreed upon this.
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 15 ++++++++++++---
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> 2 files changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index a7858a1..ff5c3c7 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -413,8 +413,10 @@ void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
> dev_priv->display.force_wake_put(dev_priv);
> }
>
> -void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
> +int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
> {
> + int ret = 0;
> +
> if (dev_priv->gt_fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES) {
> int loop = 500;
> u32 fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
> @@ -422,10 +424,13 @@ void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
> udelay(10);
> fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
> }
> - WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES);
> + WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES &&
> + ++ret);
Bit a bikeshed comment, but I prefer explicit control flow instead of
playing tricks with the short-circuiting behaviour of &&. Mind if you can
change that, too?
-Daniel
--
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
