devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Rameshwar Prasad Sahu <rsahu-qTEPVZfXA3Y@public.gmane.org>
To: vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	arnd-r2nGTMty4D4@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
	patches-qTEPVZfXA3Y@public.gmane.org,
	Rameshwar Prasad Sahu <rsahu-qTEPVZfXA3Y@public.gmane.org>
Subject: [PATCH v2] dmaengine: xgene-dma: Disable memcpy operation due to performance drop
Date: Thu,  8 Oct 2015 14:36:57 +0530	[thread overview]
Message-ID: <1444295217-3099-1-git-send-email-rsahu@apm.com> (raw)

The DMA engine supports memory copy, RAID5 XOR, RAID6 PQ, and other
computations. But the bandwidth of the entire DMA engine is shared
among all channels. This patch re-configures operations availability
such that one can achieve maximum performance for XOR and PQ
computation by removing the memory offload operations.

Signed-off-by: Rameshwar Prasad Sahu <rsahu-qTEPVZfXA3Y@public.gmane.org>
---
 drivers/dma/xgene-dma.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
index 8d57b1b..cd38022 100644
--- a/drivers/dma/xgene-dma.c
+++ b/drivers/dma/xgene-dma.c
@@ -1707,7 +1707,6 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
 	dma_cap_zero(dma_dev->cap_mask);

 	/* Set DMA device capability */
-	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
 	dma_cap_set(DMA_SG, dma_dev->cap_mask);

 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
--
1.8.2.1

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

             reply	other threads:[~2015-10-08  9:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-08  9:06 Rameshwar Prasad Sahu [this message]
2015-10-09 16:12 ` [PATCH v2] dmaengine: xgene-dma: Disable memcpy operation due to performance drop Vinod Koul
     [not found]   ` <20151009161208.GJ3609-bQVUxfxUtC13uc1i7fC1zK2pdiUAq4bhAL8bYrjMMd8@public.gmane.org>
2015-10-09 16:38     ` Rameshwar Sahu
2015-10-12 14:23       ` Vinod Koul
2015-10-14 10:20         ` Rameshwar Sahu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1444295217-3099-1-git-send-email-rsahu@apm.com \
    --to=rsahu-qtepvzfxa3y@public.gmane.org \
    --cc=arnd-r2nGTMty4D4@public.gmane.org \
    --cc=dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
    --cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=patches-qTEPVZfXA3Y@public.gmane.org \
    --cc=vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).