Removed the residual rest to zero on last descriptor. Also set residue granularity to BURST instead of SEGMENT. This last item needs more investigation before I could give a rationale for it.
Signed-off-by: Alban Browaeys <[email protected]> Reported-by: [email protected] Reported-by: Krzysztof Kozlowski <[email protected]> Fixes: aee4d1fac887 ("dmaengine: pl330: improve pl330_tx_status() function") --- My older local version of the residue : https://github.com/prahal/linux/blob/odroid-3.19/drivers/dma/pl330.c#L2230 I took a second look at both and noticed that in the upstream version, I was not able to make sense of the "if desc->last then reset residual to zero" in the loop. Early tests gives a proper sound ouput with it removed. More tests are welcome, and it could be the flag change is wrong. There is also a bad interaction with pulseaudio when the buffer size is small : https://bugs.freedesktop.org/show_bug.cgi?id=84878. This might affect testing. --- drivers/dma/pl330.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index f513f77..0851f41 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2275,8 +2275,6 @@ pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie, } break; } - if (desc->last) - residual = 0; } spin_unlock_irqrestore(&pch->lock, flags); @@ -2890,7 +2888,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) pd->src_addr_widths = PL330_DMA_BUSWIDTHS; pd->dst_addr_widths = PL330_DMA_BUSWIDTHS; pd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); - pd->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; + pd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; ret = dma_async_device_register(pd); if (ret) { -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
