Commit 7127941c authored by Alan Stern's avatar Alan Stern Committed by Chris Wright

USB: usb-storage: increase max_sectors for tape drives

upstream commit: 5c16034d

This patch (as1203) increases the max_sector limit for USB tape
drives.  By default usb-storage sets max_sectors to 240 (i.e., 120 KB)
for all devices.  But tape drives need a higher limit, since tapes can
and do have very large block sizes.  Without the ability to transfer
an entire large block in a single command, such tapes can't be used.

This fixes Bugzilla #12207.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: default avatarPhil Mitchell <philipm@sybase.com>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarChris Wright <chrisw@sous-sol.org>
parent 760053b6
......@@ -135,6 +135,12 @@ static int slave_configure(struct scsi_device *sdev)
if (sdev->request_queue->max_sectors > max_sectors)
blk_queue_max_sectors(sdev->request_queue,
max_sectors);
} else if (sdev->type == TYPE_TAPE) {
/* Tapes need much higher max_sector limits, so just
* raise it to the maximum possible (4 GB / 512) and
* let the queue segment size sort out the real limit.
*/
blk_queue_max_sectors(sdev->request_queue, 0x7FFFFF);
}
/* Some USB host controllers can't do DMA; they have to use PIO.
......
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