4 files changed, 14 insertions, 2 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a92c5ebf373e..c68634edd451 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2932,6 +2932,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                                         initial READ(10) command);
                                 o = CAPACITY_OK (accept the capacity
                                         reported by the device);
+                                p = WRITE_CACHE (the device cache is ON
+                                        by default);
                                 r = IGNORE_RESIDUE (the device reports
                                         bogus residue values);
                                 s = SINGLE_LUN (the device has only one
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 11418da9bc09..a3d54366afcc 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -236,6 +236,11 @@ static int slave_configure(struct scsi_device *sdev)
                                         US_FL_SCM_MULT_TARG)) &&
                                 us->protocol == USB_PR_BULK)
                         us->use_last_sector_hacks = 1;
+
+                /* Check if write cache default on flag is set or not */
+                if (us->fflags & US_FL_WRITE_CACHE)
+                        sdev->wce_default_on = 1;
+
         } else {
 
                 /* Non-disk-type devices don't need to blacklist any pages
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index e23c30ab66da..d012fe4329e7 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -473,7 +473,7 @@ static void adjust_quirks(struct us_data *us)
                         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 @@ static void adjust_quirks(struct us_data *us)
                 case 'o':
                         f |= US_FL_CAPACITY_OK;
                         break;
+                case 'p':
+                        f |= US_FL_WRITE_CACHE;
+                        break;
                 case 'r':
                         f |= US_FL_IGNORE_RESIDUE;
                         break;
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 17df3600bcef..e84e769aaddc 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -64,7 +64,9 @@
         US_FLAG(NO_READ_CAPACITY_16,    0x00080000)             \
                 /* cannot handle READ_CAPACITY_16 */            \
         US_FLAG(INITIAL_READ10, 0x00100000)                     \
-                /* Initial READ(10) (and others) must be retried */
+                /* Initial READ(10) (and others) must be retried */     \
+        US_FLAG(WRITE_CACHE,    0x00200000)                     \
+                /* Write Cache status is not available */
 
 #define US_FLAG(name, value)    US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };