On Tue, Feb 07, 2012 at 04:21:49PM +0100, Ben Widawsky wrote:
> This is similar to a patch I wrote several months ago. It's been updated
> for the new FORCEWAKE_MT, and it also no longer clears the debug
> register as it may be helpful to get that for the error state. Also
> recommended by Chris Wilson, use WARN() instead of DRM_ERROR, so we can
> get a backtrace.
>
> v2: Replace POSTING_READ with I915_READ_NOTRACE(GTFIFODBG). Recommended
> by Chris Wilson
>
> v3: Pull the fifo check out into a helper function to reduce code
> duplication
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 15 +++++++++++++--
> 1 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 1658cfd..a7858a1 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -379,16 +379,27 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
> dev_priv->display.force_wake_get(dev_priv);
> }
>
> +static void gen6_gt_check_fifodbg(struct drm_i915_private *dev_priv)
> +{
> + u32 gtfifodbg;
> + gtfifodbg = I915_READ_NOTRACE(GTFIFODBG);
> + WARN(gtfifodbg & GT_FIFO_CPU_ERROR_MASK,
> + "MMIO read or write has been dropped %x\n", gtfifodbg);
> + I915_WRITE_NOTRACE(GTFIFODBG, GT_FIFO_CPU_ERROR_MASK);
I think we should move the write out of line and only do it when we're
actually catching an error.
-Daniel
--
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
