alim15x3: add "wdc_udma" module parameter
Add "wdc_udma" module parameter for allowing UDMA transfers
on M1543C-E chipset for WDC disks.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/alim15x3.c b/drivers/ide/pci/alim15x3.c
index 98ecf14..3eaab54 100644
--- a/drivers/ide/pci/alim15x3.c
+++ b/drivers/ide/pci/alim15x3.c
@@ -39,6 +39,16 @@
#include <asm/io.h>
/*
+ * Allow UDMA on M1543C-E chipset for WDC disks that ignore CRC checking
+ * (this is DANGEROUS and could result in data corruption).
+ */
+static int wdc_udma;
+
+module_param(wdc_udma, bool, 0);
+MODULE_PARM_DESC(wdc_udma,
+ "allow UDMA on M1543C-E chipset for WDC disks (DANGEROUS)");
+
+/*
* ALi devices are not plug in. Otherwise these static values would
* need to go. They ought to go away anyway
*/
@@ -116,7 +126,7 @@
* The actual rules for the ALi are:
* No UDMA on revisions <= 0x20
* Disk only for revisions < 0xC2
- * Not WDC drives for revisions < 0xC2
+ * Not WDC drives on M1543C-E (?)
*
* FIXME: WDC ifdef needs to die
*/
@@ -127,7 +137,8 @@
if (drive->media != ide_disk)
return 0;
#ifndef CONFIG_WDC_ALI15X3
- if (chip_is_1543c_e && strstr(drive->id->model, "WDC "))
+ if (chip_is_1543c_e && strstr(drive->id->model, "WDC ") &&
+ wdc_udma == 0)
return 0;
#endif
}