From 5c16034d73da2c1b663aa25dedadbc533b3d811c Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 23 Mar 2009 09:51:02 -0400 Subject: [PATCH] USB: usb-storage: increase max_sectors for tape drives 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 Reported-and-tested-by: Phil Mitchell Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/scsiglue.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 727c506417cc..ed710bcdaab2 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -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. -- GitLab