From: Li Yang <leoli@freescale.com>
To: <dan.j.williams@intel.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] fsldma: fix issue of slow dma
Date: Thu, 9 Dec 2010 16:14:04 +0800 [thread overview]
Message-ID: <1291882444-1523-1-git-send-email-leoli@freescale.com> (raw)
From: Forrest Shi <b29237@freescale.com>
Fixed fsl dma slow issue by initializing dma mode register with
bandwidth control. It boosts dma performance and should works
with 85xx board.
Signed-off-by: Forrest Shi <b29237@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
---
drivers/dma/fsldma.c | 6 ++++--
drivers/dma/fsldma.h | 9 ++++++++-
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 286c3ac..e5e172d 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -50,9 +50,11 @@ static void dma_init(struct fsldma_chan *chan)
* EIE - Error interrupt enable
* EOSIE - End of segments interrupt enable (basic mode)
* EOLNIE - End of links interrupt enable
+ * BWC - Bandwidth sharing among channels
*/
- DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EIE
- | FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
+ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
+ | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE
+ | FSL_DMA_MR_EOSIE, 32);
break;
case FSL_DMA_IP_83XX:
/* Set the channel to below modes:
diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
index cb4d6ff..ba9f403 100644
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
*
* Author:
* Zhang Wei <wei.zhang@freescale.com>, Jul 2007
@@ -36,6 +36,13 @@
#define FSL_DMA_MR_DAHE 0x00002000
#define FSL_DMA_MR_SAHE 0x00001000
+/*
+ * Bandwidth/pause control determines how many bytes a given
+ * channel is allowed to transfer before the DMA engine pauses
+ * the current channel and switches to the next channel
+ */
+#define FSL_DMA_MR_BWC 0x08000000
+
/* Special MR definition for MPC8349 */
#define FSL_DMA_MR_EOTIE 0x00000080
#define FSL_DMA_MR_PRC_RM 0x00000800
--
1.6.6-rc1.GIT
next reply other threads:[~2010-12-09 7:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-09 8:14 Li Yang [this message]
2010-12-13 22:02 ` [PATCH] fsldma: fix issue of slow dma Dan Williams
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=1291882444-1523-1-git-send-email-leoli@freescale.com \
--to=leoli@freescale.com \
--cc=dan.j.williams@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.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).