From eeee4107546ef24c739d72645899e50fa693e9ff Mon Sep 17 00:00:00 2001 From: Yadan Fan Date: Fri, 23 Jun 2017 17:40:06 +0800 Subject: [PATCH] scsi: smartpqi: limit transfer length to 1MB 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 in kernels later than v4.3 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. Signed-off-by: Yadan Fan Reviewed-by: Johannes Thumshirn Acked-by: Don Brace Signed-off-by: Martin K. Petersen --- 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 07ec8a8877de..e164ffade38a 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -690,7 +690,7 @@ struct pqi_config_table_heartbeat { #define PQI_MAX_OUTSTANDING_REQUESTS ((u32)~0) #define PQI_MAX_OUTSTANDING_REQUESTS_KDUMP 32 -#define PQI_MAX_TRANSFER_SIZE (4 * 1024U * 1024U) +#define PQI_MAX_TRANSFER_SIZE (1024U * 1024U) #define PQI_MAX_TRANSFER_SIZE_KDUMP (512 * 1024U) #define RAID_MAP_MAX_ENTRIES 1024 -- 2.45.2