tx4939ide: Do not use zero count PRD entry
This fixes data corruption on some heavy load.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: stable <stable@kernel.org>
Cc: sshtylyov@ru.mvista.com
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/tx4939ide.c b/drivers/ide/tx4939ide.c
index bafb7d1..30d0d25 100644
--- a/drivers/ide/tx4939ide.c
+++ b/drivers/ide/tx4939ide.c
@@ -259,6 +259,12 @@
bcount = 0x10000 - (cur_addr & 0xffff);
if (bcount > cur_len)
bcount = cur_len;
+ /*
+ * This workaround for zero count seems required.
+ * (standard ide_build_dmatable do it too)
+ */
+ if ((bcount & 0xffff) == 0x0000)
+ bcount = 0x8000;
*table++ = bcount & 0xffff;
*table++ = cur_addr;
cur_addr += bcount;
