On Thu, 2013-12-05 at 11:29 +0900, Michel Dänzer wrote: > On Don, 2013-12-05 at 12:39 +1100, Benjamin Herrenschmidt wrote: > > On Wed, 2013-12-04 at 19:05 -0500, Alex Deucher wrote: > > > > > > Setting CP_RB_CNTL.BUF_SWAP causes the CP to use the selected byte > > > > swapping for just about everything accessed by the CP (rptr writeback, > > > > indirect buffers, etc.). Looks like the DMA ring supports and enables > > > > rptr writeback as well (DMA_RB_CNTL.DMA_RPTR_WRITEBACK_SWAP_ENABLE) so > > > > I think we can drop the swapping of the rptr writeback. > > > > > > > > > > Obvious patch attached. > > > > This works all the way back to r300 ? > > I don't think so, as I have writeback working without this patch on the > RV350 in this PowerBook. So I think this function needs to be split, > probably between R600 and older. Or can we tell it to not swap (setup code) and continue doing le32_to_cpu in the kernel ? Sounds better to me. > Also, there's more code at least potentially affected by this, e.g. in: > > * cik_compute_ring_get_rptr(), cik_compute_ring_get_wptr(), > cik_compute_ring_set_wptr(), cik_get_ih_wptr() > * si_get_ih_wptr() > * evergreen_get_ih_wptr() > * r600_get_ih_wptr() > * radeon_fence_write(), radeon_fence_read() > * radeon_ring_backup() Yeah I'd say just don't swap, write LE to memory and let the kernel use the right leXX_to_cpu. HW swapping is evil :-) Cheers, Ben. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
