Some SATA to USB bridges fail to cooperate with some
drives resulting in no cache being present being reported
to the host. That causes the host to skip sending
a command to synchronize caches. That causes data loss
when the drive is powered down.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
---
Documentation/kernel-parameters.txt | 2 ++
drivers/usb/storage/scsiglue.c | 8 ++++++++
drivers/usb/storage/unusual_devs.h | 7 +++++++
drivers/usb/storage/usb.c | 6 +++++-
include/linux/usb_usual.h | 2 ++
5 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 82b42c9..c8c682e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -4182,6 +4182,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
u = IGNORE_UAS (don't bind to the uas driver);
w = NO_WP_DETECT (don't test whether the
medium is write-protected).
+ y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE
+ even if the device claims no cache)
Example: quirks=0419:aaf5:rl,0421:0433:rc
user_debug= [KNL,ARM]
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 33eb923..8cd2926 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -296,6 +296,14 @@ static int slave_configure(struct scsi_device *sdev)
if (us->fflags & US_FL_BROKEN_FUA)
sdev->broken_fua = 1;
+ /* Some even totally fail to indicate a cache */
+ if (us->fflags & US_FL_ALWAYS_SYNC) {
+ /* don't read caching information */
+ sdev->skip_ms_page_8 = 1;
+ sdev->skip_ms_page_3f = 1;
+ /* assume sync is needed */
+ sdev->wce_default_on = 1;
+ }
} else {
/*
diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h
index aa35392..af3c7ee 100644
--- a/drivers/usb/storage/unusual_devs.h
+++ b/drivers/usb/storage/unusual_devs.h
@@ -338,6 +338,13 @@ UNUSUAL_DEV( 0x046b, 0xff40, 0x0100, 0x0100,
USB_SC_DEVICE, USB_PR_DEVICE, NULL,
US_FL_NO_WP_DETECT),
+/* Reported by Egbert Eich <eich@xxxxxxxx> */
+UNUSUAL_DEV( 0x0480, 0xd010, 0x0100, 0x9999,
+ "Toshiba",
+ "External USB 3.0",
+ USB_SC_DEVICE, USB_PR_DEVICE, NULL,
+ US_FL_ALWAYS_SYNC),
+
/* Patch submitted by Philipp Friedrich <philipp@xxxxxxx> */
UNUSUAL_DEV( 0x0482, 0x0100, 0x0100, 0x0100,
"Kyocera",
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index ef2d8cd..19255f1 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -498,7 +498,8 @@ void usb_stor_adjust_quirks(struct usb_device *udev, unsigned long *fflags)
US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16 |
US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE |
US_FL_NO_ATA_1X | US_FL_NO_REPORT_OPCODES |
- US_FL_MAX_SECTORS_240 | US_FL_NO_REPORT_LUNS);
+ US_FL_MAX_SECTORS_240 | US_FL_NO_REPORT_LUNS |
+ US_FL_ALWAYS_SYNC);
p = quirks;
while (*p) {
@@ -581,6 +582,9 @@ void usb_stor_adjust_quirks(struct usb_device *udev, unsigned long *fflags)
case 'w':
f |= US_FL_NO_WP_DETECT;
break;
+ case 'y':
+ f |= US_FL_ALWAYS_SYNC;
+ break;
/* Ignore unrecognized flag characters */
}
}
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 245f57d..0aae1b2 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -81,6 +81,8 @@
/* Sets max_sectors to 240 */ \
US_FLAG(NO_REPORT_LUNS, 0x10000000) \
/* Cannot handle REPORT_LUNS */ \
+ US_FLAG(ALWAYS_SYNC, 0x20000000) \
+ /* lies about caching, so always sync */ \
#define US_FLAG(name, value) US_FL_##name = value ,
enum { US_DO_ALL_FLAGS };
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
