Re: [PATCH] dmaengine: pl330: _prep_dma_memcpy: Fix wrong burst size

From: Vinod Koul
Date: Mon Nov 16 2020 - 12:15:21 EST


On 14-11-20, 11:55, Sugar Zhang wrote:
> Actually, burst size is equal to '1 << desc->rqcfg.brst_size'.
> we should use burst size, not desc->rqcfg.brst_size.
>
> dma memcpy performance on Rockchip RV1126
> @ 1512MHz A7, 1056MHz LPDDR3, 200MHz DMA:
>
> dmatest:
>
> /# echo dma0chan0 > /sys/module/dmatest/parameters/channel
> /# echo 4194304 > /sys/module/dmatest/parameters/test_buf_size
> /# echo 8 > /sys/module/dmatest/parameters/iterations
> /# echo y > /sys/module/dmatest/parameters/norandom
> /# echo y > /sys/module/dmatest/parameters/verbose
> /# echo 1 > /sys/module/dmatest/parameters/run
>
> dmatest: dma0chan0-copy0: result #1: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #2: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #3: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #4: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #5: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #6: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #7: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
> dmatest: dma0chan0-copy0: result #8: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
>
> Before:
>
> dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 48 iops 200338 KB/s (0)
>
> After this patch:
>
> dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 179 iops 734873 KB/s (0)
>
> After this patch and increase dma clk to 400MHz:
>
> dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 259 iops 1062929 KB/s (0)

Applied, thanks

--
~Vinod