[Intel-gfx] [PATCH 15/17] drm/i915/bdw: collect semaphore error state

[Ben Widawsky]

On Fri, Dec 13, 2013 at 08:16:03PM -0800, Ben Widawsky wrote:
> Since the semaphore information is in an object, just dump it, and let
> the user parse it later.
> 
> NOTE: The page being used for the semaphores are incoherent with the
> CPU. No matter what I do, I cannot figure out a way to read anything but
> 0s. Note that the semaphore waits are indeed working.
> 
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
>  

[snip]

> +static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
> +					struct drm_i915_error_state *error,
> +					struct intel_ring_buffer *ring)
> +{
> +	struct intel_ring_buffer *useless;
> +	int i;
> +
> +	if (!i915_semaphore_is_enabled(dev_priv->dev))
> +		return;
> +
> +	if (!error->semaphore_obj)
> +		error->semaphore_obj =
> +			i915_error_object_create(dev_priv,
> +						 dev_priv->semaphore_obj);
> +
> +	for_each_ring(useless, dev_priv, i) {
> +		u16 signal_offset = GEN8_SIGNAL_OFFSET(ring, i) / 4;
> +		u16 wait_offset = GEN8_WAIT_OFFSET(ring, i) / 4;
> +		u32 *tmp = error->semaphore_obj->pages[0];
> +
> +		error->semaphore_mboxes[ring->id][i] = tmp[signal_offset];
> +		error->semaphore_seqno[ring->id][i] = tmp[wait_offset];
> +	}
> +}
> +

Chris, I preemptively assume this rubs you the wrong way. I had been
trying to do the analogous of the I915_READ from previous gens. I felt
it was more consistent with reading of hardware state. If you want me to
simply use the ring->semaphore.*, I can. I just wanted to make my
intention clear.


[snip]

-- 
Ben Widawsky, Intel Open Source Technology Center