[SCSI] usb-storage: add support for write cache quirk
Add support for write cache quirk on usb hdd. scsi driver will be set to wce
by detecting write cache quirk in quirk list when plugging usb hdd.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index e23c30a..d012fe4 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -473,7 +473,7 @@
US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16 |
- US_FL_INITIAL_READ10);
+ US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE);
p = quirks;
while (*p) {
@@ -529,6 +529,9 @@
case 'o':
f |= US_FL_CAPACITY_OK;
break;
+ case 'p':
+ f |= US_FL_WRITE_CACHE;
+ break;
case 'r':
f |= US_FL_IGNORE_RESIDUE;
break;