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| author | Doug Maxey <dwm@enoyolf.org> | 2007-12-05 23:36:45 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-12-17 10:47:14 -0800 |
| commit | 33abc04f0420dceed0ebc2d1094019d3bb2b5c29 (patch) | |
| tree | 87d8e2c7cf41d6afed4d75c2e3ef113b506541ab /drivers/usb/storage/scsiglue.c | |
| parent | b9e13ac30f850313be9232497ff98e90c43bc6b6 (diff) | |
| download | blackbird-op-linux-33abc04f0420dceed0ebc2d1094019d3bb2b5c29.tar.gz blackbird-op-linux-33abc04f0420dceed0ebc2d1094019d3bb2b5c29.zip | |
usb-storage: Fix devices that cannot handle 32k transfers
When a device cannot handle the smallest previously limited transfer
size (64 blocks) without stalling, limit the device to the amount of
packets that fit in a platform native page.
The lowest possible limit is PAGE_CACHE_SIZE, so if the device is ever
used on a platform that has larger than 8K pages, you lose unless you
can convince the device firmware folks to fix the issue.
Cc: Mathew Dharm <mdharm-scsi@one-eyed-alien.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Doug Maxey <dwm@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/storage/scsiglue.c')
| -rw-r--r-- | drivers/usb/storage/scsiglue.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 836a34ae6ec6..7c9593b7b04e 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -114,9 +114,15 @@ static int slave_configure(struct scsi_device *sdev) * while others have trouble with more than 64K. At this time we * are limiting both to 32K (64 sectores). */ - if ((us->flags & US_FL_MAX_SECTORS_64) && - sdev->request_queue->max_sectors > 64) - blk_queue_max_sectors(sdev->request_queue, 64); + if (us->flags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { + unsigned int max_sectors = 64; + + if (us->flags & US_FL_MAX_SECTORS_MIN) + max_sectors = PAGE_CACHE_SIZE >> 9; + if (sdev->request_queue->max_sectors > max_sectors) + blk_queue_max_sectors(sdev->request_queue, + max_sectors); + } /* We can't put these settings in slave_alloc() because that gets * called before the device type is known. Consequently these |
