[Intel-gfx] [PATCH] drm/i915/dp: Add branch/sink OUI debugging

[Keith Packard]

On Fri, 13 Jan 2012 13:26:08 -0500, Adam Jackson <ajax at redhat.com> wrote:

> +	count &= (~DP_DOWN_STREAM_OUI_SUPPORTED);
> +	if ((count & DP_DOWN_STREAM_PORT_COUNT_MASK) == 0)
> +		offset = DP_SINK_IEEE_OUI;
> +	else
> +		offset = DP_BRANCH_IEEE_OUI_OUT;

I suspect the SINK_IEEE_OUI will be more relevant than the
BRANCH_IEEE_OUI, but if you're going to the trouble to tell that there
is a downstream device, perhaps you should just report both?


> +#define DP_DOWN_STREAM_PORT_COUNT	    0x007
> +# define DP_DOWN_STREAM_PORT_COUNT_MASK	    0x0f
> +# define DP_DOWN_STREAM_OUI_SUPPORTED	    (1 << 7)
> +

> +#define DP_SOURCE_IEEE_OUI		    0x300
> +#define DP_SINK_IEEE_OUI		    0x400
> +#define DP_BRANCH_IEEE_OUI		    0x500
> +

These definitions match the DP spec, and the code uses them correctly.

So, the code looks like it will work, the only question I have is
whether the BRANCH or SINK would be more useful for debugging
problems...

Reviewed-by: Keith Packard <keithp at keithp.com>

-- 
keith.packard at intel.com
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