From: Maxime Ripard Date: Tue, 15 Sep 2015 13:36:00 +0000 (+0200) Subject: dmaengine: at_xdmac: change block increment addressing mode X-Git-Tag: v4.2.4~207 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f788de2664c2640307b93d658e2bf54f79f1192d;p=thirdparty%2Fkernel%2Fstable.git dmaengine: at_xdmac: change block increment addressing mode commit a1cf09031e641d3cceaca4a4dd20ef6a785bc9b3 upstream. 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 Signed-off-by: Ludovic Desroches Fixes: 6007ccb57744 ("dmaengine: xdmac: Add interleaved transfer support") Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 40afa2a16cfc0..6ec3c1f442be0 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -878,14 +878,14 @@ 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; }