linux-mips
[Top] [All Lists]

Re: [PATCH] au1xmmc: raise segment size limit.

To: Manuel Lauss <mano@roarinelk.homelinux.net>
Subject: Re: [PATCH] au1xmmc: raise segment size limit.
From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Date: Tue, 29 Jul 2008 02:21:36 +0400
Cc: drzeus@drzeus.cx, linux-mips@linux-mips.org
In-reply-to: <20080728133120.GB26494@roarinelk.homelinux.net>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20080728133120.GB26494@roarinelk.homelinux.net>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Thunderbird 2.0.0.16 (Windows/20080708)
Hello.

Manuel Lauss wrote:
Please apply this patch, as it fixes an oops when MMC-DMA and network
traffic are active at the same time.  This seems to be a 2.6.27-only thing;
the current au1xmmc code (minus the polling parts) works fine on 2.6.26.

---

Raise the DMA block size limit from 2048 bytes to the maximum supported
by the DMA controllers on the chip (128kB on Au1100, 4MB on Au1200).

This gives a small performance boost and apparently fixes an oops when
MMC-DMA and network traffic are active at the same time.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>

[...]
diff --git a/drivers/mmc/host/au1xmmc.c b/drivers/mmc/host/au1xmmc.c
index 99b2091..dd414f1 100644
--- a/drivers/mmc/host/au1xmmc.c
+++ b/drivers/mmc/host/au1xmmc.c
@@ -61,7 +61,13 @@
/* Hardware definitions */
 #define AU1XMMC_DESCRIPTOR_COUNT 1
-#define AU1XMMC_DESCRIPTOR_SIZE  2048
+
+/* max DMA seg size: 64kB on Au1100, 4MB on Au1200 */

 So, it's 64 or 128 KB? KB since k prefix usualy means decimal kilo... :-)

WBR, Sergei



<Prev in Thread] Current Thread [Next in Thread>