Messages in this thread Patch in this message | | | From | Ludovic Desroches <> | Subject | [PATCH 2/4] dmaengine: at_xdmac: change block increment addressing mode | Date | Tue, 15 Sep 2015 15:36:00 +0200 |
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From: Maxime Ripard <maxime.ripard@free-electrons.com>
The addressing mode we were using was not only incrementing the address at each microblock, but also at each data boundary, which was severely slowing the transfer, without any benefit since we were not using the data stride.
Switch to the micro block increment only in order to get back to an acceptable performance level.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Fixes: 6007ccb57744 ("dmaengine: xdmac: Add interleaved transfer support") Cc: stable@vger.kernel.org #4.2 --- drivers/dma/at_xdmac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 0190d1c..3952bff 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -875,14 +875,14 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan, if (xt->src_inc) { if (xt->src_sgl) - chan_cc |= AT_XDMAC_CC_SAM_UBS_DS_AM; + chan_cc |= AT_XDMAC_CC_SAM_UBS_AM; else chan_cc |= AT_XDMAC_CC_SAM_INCREMENTED_AM; } if (xt->dst_inc) { if (xt->dst_sgl) - chan_cc |= AT_XDMAC_CC_DAM_UBS_DS_AM; + chan_cc |= AT_XDMAC_CC_DAM_UBS_AM; else chan_cc |= AT_XDMAC_CC_DAM_INCREMENTED_AM; } -- 2.5.0
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