On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede hdegoede@redhat.com wrote:
Hi,
On 04-01-15 20:19, Michal Suchanek wrote:
Setting magic 'reserved' hpcr bit on sun5i DEBE seems required for smooth HDMI scanout of large frambuffer (eg. 1080p).
This fix comes at the cost of some overall memory bandwidth so it might be appropriate to detect a10s and only apply there (and not a13).
Hmm, Sairhei is the expert on this, adding him to the Cc. Sairhei, what do you think of the proposed change ?
I don't have A10s hardware, so have no idea and can't test anything myself.
It would be great to have a better description of what exactly is happening before the patch. And precisely how the patch is helping. A description of the test setup and benchmark numbers would be appreciated. And it would be perfect if somebody else could reproduce the test and confirm the results.
I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.