From: Ian Jackson <iwj@mariner.uk.xensource.com>
Date: Tue, 15 Jul 2008 17:40:04 +0000 (+0100)
Subject: Saner calculation of stubdom IDE_DMA_BUF_SECTORS.
X-Git-Tag: xen-3.3.0-rc1~30
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=2102c06b1fdb0ea0e3cae56311fce3be7118b306;p=qemu-xen-4.0-testing.git

Saner calculation of stubdom IDE_DMA_BUF_SECTORS.

Thanks to Samuel Thibault.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
---

diff --git a/hw/ide.c b/hw/ide.c
index 37bcf56b..79c52040 100644
--- a/hw/ide.c
+++ b/hw/ide.c
@@ -201,20 +201,10 @@
 
 /* set to 1 set disable mult support */
 #define MAX_MULT_SECTORS 16
-#ifdef CONFIG_STUBDOM
-#include <xen/io/blkif.h>
-#define IDE_DMA_BUF_SIZE (BLKIF_MAX_SEGMENTS_PER_REQUEST * TARGET_PAGE_SIZE)
-#else
-#define IDE_DMA_BUF_SIZE 131072
-#endif
-#if (IDE_DMA_BUF_SIZE < MAX_MULT_SECTORS * 512)
-#error "IDE_DMA_BUF_SIZE must be bigger or equal to MAX_MULT_SECTORS * 512"
-#endif
-
 #ifdef CONFIG_STUBDOM
 #include <xen/io/blkif.h>
 #define IDE_DMA_BUF_SECTORS \
- ((BLKIF_MAX_SEGMENTS_PER_REQUEST * TARGET_PAGE_SIZE) / 512)
+	(((BLKIF_MAX_SEGMENTS_PER_REQUEST - 1 ) * TARGET_PAGE_SIZE) / 512)
 #else
 #define IDE_DMA_BUF_SECTORS 256
 #endif