Commits
Laurent Pinchart committed 1ed1315f9b6
dmaengine: rcar-dmac: Cache hardware descriptors memory Unlike DMA transfers descriptors that are preallocated and cached, memory used to store hardware descriptors is allocated and freed with the DMA coherent allocation API for every transfer. Besides degrading performances, this creates a CMA stress test that seems to cause issues. Running dmatest with the noverify option produces [ 50.066539] alloc_contig_range test_pages_isolated(6b845, 6b846) failed [ 50.235180] alloc_contig_range test_pages_isolated(6b848, 6b84e) failed [ 52.964584] alloc_contig_range test_pages_isolated(6b847, 6b848) failed [ 54.127113] alloc_contig_range test_pages_isolated(6b843, 6b844) failed [ 56.270253] alloc_contig_range test_pages_isolated(6b84c, 6b850) failed The root cause needs to be fixed, but in the meantime, as a workaround and a performance improvement, cache hardware descriptors. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>