USB: usb-storage: increase max_sectors for tape drives (5c16034d) · Commits · e / devices / android_kernel_teracube_2e

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:

Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by:

Phil Mitchell <philipm@sybase.com> Cc: stable <stable@kernel.org> Signed-off-by:

Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/storage/scsiglue.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -135,6 +135,12 @@ static int slave_configure(struct scsi_device *sdev)
	if (sdev->request_queue->max_sectors > max_sectors)		if (sdev->request_queue->max_sectors > max_sectors)
	blk_queue_max_sectors(sdev->request_queue,		blk_queue_max_sectors(sdev->request_queue,
	max_sectors);		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.		/* Some USB host controllers can't do DMA; they have to use PIO.