From 61bf54b71d5abf767ee46284be19965d7253ddbf Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 8 Feb 2007 09:04:48 +0100 Subject: USB Storage: indistinguishable devices with broken and unbroken firmware there's a USB mass storage device which exists in two version. One reports the correct size and the other does not. Apart from that they are identical and cannot be told apart. Here's a heuristic based on the empirical finding that drives have even sizes. Signed-off-by: Oliver Neukum Acked-by: Alan Stern Acked-by: Matthew Dharm Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sd.c | 11 ++++++++++- drivers/usb/storage/scsiglue.c | 6 ++++++ drivers/usb/storage/unusual_devs.h | 2 +- 3 files changed, 17 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3f048bd6326..5a8f55fea5f 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 70234f5dbee..e227f64d564 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 bab054b8d94..56836656976 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), -- cgit v1.2.3