From: Yadan Fan <ydfan@suse.com>
Date: Fri, 23 Jun 2017 09:40:05 +0000 (+0800)
Subject: scsi: hpsa: limit transfer length to 1MB
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e2c7b433f729cedb32514480af8cbdf2fe5cf264;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

scsi: hpsa: limit transfer length to 1MB

The hpsa 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 hpsa driver.

Signed-off-by: Yadan Fan <ydfan@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 8914eab84337..4f7cdb28bd38 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -938,7 +938,7 @@ static struct scsi_host_template hpsa_driver_template = {
 #endif
 	.sdev_attrs = hpsa_sdev_attrs,
 	.shost_attrs = hpsa_shost_attrs,
-	.max_sectors = 8192,
+	.max_sectors = 1024,
 	.no_write_same = 1,
 };