linux-kernel - [PATCH 07/18] DMA: edma: Use different eventq for cyclic channels

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 13 Mar 2014 11:18:29 +0200
From:	Peter Ujfalusi <peter.ujfalusi@...com>
To:	<linux-kernel@...r.kernel.org>, <alsa-devel@...a-project.org>,
	<linux-omap@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>, <dmaengine@...r.kernel.org>
CC:	<davinci-linux-open-source@...ux.davincidsp.com>, <joelf@...com>,
	Mark Brown <broonie@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Tony Lindgren <tony@...mide.com>, <nsekhar@...com>,
	Jyri Sarha <jsarha@...com>, <mporter@...aro.org>,
	<vinod.koul@...el.com>, <dan.j.williams@...el.com>
Subject: [PATCH 07/18] DMA: edma: Use different eventq for cyclic channels

To improve latency with cyclic DMA operation it is preferred to
use different eventq/tc than the default which is used by all
other drivers (mmc, spi, i2c, etc).
When preparing the cyclic dma ask for non default queue for the
channel which is going to be used with cyclic mode.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
---
 drivers/dma/edma.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 86d6a3fb0d92..604c7c94c731 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -624,6 +624,9 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic(
 		edesc->pset[i].opt |= TCINTEN;
 	}
 
+	/* Use different eventq/tc for cyclic DMA to reduce latency */
+	edma_request_non_default_queue(echan->ch_num);
+
 	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
 }
 
-- 
1.9.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/