From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yadan Fan Subject: [PATCH 2/2] smartpqi: limit transfer length to 1MB Date: Thu, 22 Jun 2017 17:58:45 +0800 Message-ID: <20170622095845.4235-2-ydfan@suse.com> References: <20170622095845.4235-1-ydfan@suse.com> Return-path: In-Reply-To: <20170622095845.4235-1-ydfan@suse.com> Sender: linux-kernel-owner@vger.kernel.org To: don.brace@microsemi.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: esc.storagedev@microsemi.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, ydfan@suse.com List-Id: linux-scsi@vger.kernel.org The smartpqi firmware will bypass the cache for any request larger than 1MB, so we should cap the request size to avoid any performance degradation on SLE12-SP2 This degradation is caused from d2be537c3ba3568acd79cd178327b842e60d035e, which changed max_sectors_kb to 1280k, but the hardware is able to work fine with it, so the true fix should be from smartpqi driver. Reference: bsc#1025461 Signed-off-by: Yadan Fan --- drivers/scsi/smartpqi/smartpqi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index b673825f46b5..9513357bd472 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -630,7 +630,7 @@ struct pqi_encryption_info { }; #define PQI_MAX_OUTSTANDING_REQUESTS ((u32)~0) -#define PQI_MAX_TRANSFER_SIZE (4 * 1024U * 1024U) +#define PQI_MAX_TRANSFER_SIZE (1024U * 1024U) #define RAID_MAP_MAX_ENTRIES 1024 -- 2.12.3