mpt2sas: Correct resizing calculation for max_queue_depth

commit 11e1b961ab067ee3acaf723531da4d3f23e1d6f7 upstream.

The ioc->hba_queue_depth is not properly resized when the controller
firmware reports that it supports more outstanding IO than what can be fit
inside the reply descriptor pool depth. This is reproduced by setting the
controller global credits larger than 30,000. The bug results in an
incorrect sizing of the queues. The fix is to resize the queue_size by
dividing queue_diff by two.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index 670241efa4b555041e5b4fcb88cfe27929709d50..b4eff3cb57ff60552ce80f8046c6605dabc2af8c 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1947,9 +1947,9 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc,  int sleep_flag)
                /* adjust hba_queue_depth, reply_free_queue_depth,
                 * and queue_size
                 */
-               ioc->hba_queue_depth -= queue_diff;
-               ioc->reply_free_queue_depth -= queue_diff;
-               queue_size -= queue_diff;
+               ioc->hba_queue_depth -= (queue_diff / 2);
+               ioc->reply_free_queue_depth -= (queue_diff / 2);
+               queue_size = facts->MaxReplyDescriptorPostQueueDepth;
        }
        ioc->reply_post_queue_depth = queue_size;