Am Sonntag, den 16.07.2017, 16:29 +0100 schrieb Russell King - ARM Linux: > On Fri, Jul 14, 2017 at 04:38:01PM +0200, Lucas Stach wrote: > > While this is no build dependency, etnaviv will only work correctly on most > > systems if CMA and DMA_CMA are enabled. Select both options if available to > > avoid users ending up with a non-working GPU due to a lacking kernel config. > > How does merely selecting CMA solve this problem? Does CMA guarantee > that GPU command buffers will always be allocated in the lower 2G of > physical address space? No, but CMA guarantees that commandbuffers will be allocated from the region and with the default CMA configuration dma_get_required_mask() will return the correct location of the CMA area, so we can move the linear memory window accordingly. There are no guarantees, but at least with a CMA area no larger than 2GB things will work for the average user, which is a lot better than leaving them with a non-working GPU due to a simple missing kernel configuration option. Regards, Lucas _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
