[PATCH 4.2.y-ckt 132/218] USB: uas: Reduce can_queue to MAX_CMNDS

Kamal Mostafa kamal at canonical.com
Thu Mar 31 20:15:45 UTC 2016


4.2.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Hans de Goede <hdegoede at redhat.com>

commit 55ff8cfbc4e12a7d2187df523938cc671fbebdd1 upstream.

The uas driver can never queue more then MAX_CMNDS (- 1) tags and tags
are shared between luns, so there is no need to claim that we can_queue
some random large number.

Not claiming that we can_queue 65536 commands, fixes the uas driver
failing to initialize while allocating the tag map with a "Page allocation
failure (order 7)" error on systems which have been running for a while
and thus have fragmented memory.

Reported-and-tested-by: Yves-Alexis Perez <corsac at corsac.net>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/storage/uas.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 43b1caf..bf1ed71 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -812,7 +812,7 @@ static struct scsi_host_template uas_host_template = {
 	.slave_configure = uas_slave_configure,
 	.eh_abort_handler = uas_eh_abort_handler,
 	.eh_bus_reset_handler = uas_eh_bus_reset_handler,
-	.can_queue = 65536,	/* Is there a limit on the _host_ ? */
+	.can_queue = MAX_CMNDS,
 	.this_id = -1,
 	.sg_tablesize = SG_NONE,
 	.skip_settle_delay = 1,
-- 
2.7.4





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