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: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index 88e6eebc31594a757ee8ebf925f62237591f6d80..21ddd36f9e8b02c529c667af143b5755e71969ec 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -2026,9 +2026,9 @@ _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;