On Thursday 11 June 2015 07:01 PM, ville.syrjala@xxxxxxxxxxxxxxx wrote:
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> VLV/CHV have problems with 4k aligned linear scanout buffers. The VLV docs got updated at some point to say that we need to align them to 128k, just like we do on gen4. So far I've seen the problem manifest when the stride is an odd multiple of 512 bytes, and the surface address meets the following pattern '(addr & 0xf000) == 0x1000' (also == 0x2000 is problematic on VLV). The result is a starcase effect (so some pages get dropped maybe?), with a few pages here and there clearly getting scannout out at the wrong position. I've not actually been able to reproduce this problem on gen4, so it's not clear of the issue is any way related to the 128k restrictions supposedly inherited from gen4. But let's hope the 128k alignment is sufficient to hide it all. Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx> Thanks and Regards, Arun R Murthy ------------------- _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
