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-rw-r--r--drivers/scsi/sd.c11
-rw-r--r--drivers/usb/storage/scsiglue.c6
-rw-r--r--drivers/usb/storage/unusual_devs.h2
-rw-r--r--include/linux/usb_usual.h4
-rw-r--r--include/scsi/scsi_device.h1
5 files changed, 21 insertions, 3 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3f048bd6326d..5a8f55fea5ff 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1269,9 +1269,18 @@ repeat:
/* Some devices return the total number of sectors, not the
* highest sector number. Make the necessary adjustment. */
- if (sdp->fix_capacity)
+ if (sdp->fix_capacity) {
--sdkp->capacity;
+ /* Some devices have version which report the correct sizes
+ * and others which do not. We guess size according to a heuristic
+ * and err on the side of lowering the capacity. */
+ } else {
+ if (sdp->guess_capacity)
+ if (sdkp->capacity & 0x01) /* odd sizes are odd */
+ --sdkp->capacity;
+ }
+
got_data:
if (sector_size == 0) {
sector_size = 512;
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 70234f5dbeeb..e227f64d5641 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -153,6 +153,12 @@ static int slave_configure(struct scsi_device *sdev)
if (us->flags & US_FL_FIX_CAPACITY)
sdev->fix_capacity = 1;
+ /* A few disks have two indistinguishable version, one of
+ * which reports the correct capacity and the other does not.
+ * The sd driver has to guess which is the case. */
+ if (us->flags & US_FL_CAPACITY_HEURISTICS)
+ sdev->guess_capacity = 1;
+
/* Some devices report a SCSI revision level above 2 but are
* unable to handle the REPORT LUNS command (for which
* support is mandatory at level 3). Since we already have
diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h
index bab054b8d94f..568366569769 100644
--- a/drivers/usb/storage/unusual_devs.h
+++ b/drivers/usb/storage/unusual_devs.h
@@ -1434,7 +1434,7 @@ UNUSUAL_DEV( 0xed06, 0x4500, 0x0001, 0x0001,
"DataStor",
"USB4500 FW1.04",
US_SC_DEVICE, US_PR_DEVICE, NULL,
- US_FL_FIX_CAPACITY),
+ US_FL_CAPACITY_HEURISTICS),
/* Control/Bulk transport for all SubClass values */
USUAL_DEV(US_SC_RBC, US_PR_CB, USB_US_TYPE_STOR),
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 2ae76fe52ff7..1b792b9286ba 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -46,7 +46,9 @@
US_FLAG(MAX_SECTORS_64, 0x00000400) \
/* Sets max_sectors to 64 */ \
US_FLAG(IGNORE_DEVICE, 0x00000800) \
- /* Don't claim device */
+ /* Don't claim device */ \
+ US_FLAG(CAPACITY_HEURISTICS, 0x00001000) \
+ /* sometimes sizes is too big */
#define US_FLAG(name, value) US_FL_##name = value ,
enum { US_DO_ALL_FLAGS };
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ebf31b16dc49..9dd37e2f5a84 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -122,6 +122,7 @@ struct scsi_device {
unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
unsigned select_no_atn:1;
unsigned fix_capacity:1; /* READ_CAPACITY is too high by 1 */
+ unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1 */
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
unsigned int device_blocked; /* Device returned QUEUE_FULL. */
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