From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Thu, 25 Apr 2013 11:02:39 +0000 (+0200)
Subject: s390/scm_blk: allow more cluster size values
X-Git-Tag: Ubuntu-5.2.0-15.16~15871^2~2
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=bd86055fc938493259a15dc00ee77435b4d2e83f;p=mirror_ubuntu-eoan-kernel.git

s390/scm_blk: allow more cluster size values

Allow 0 and powers of 2 between 2 and 128 for write_cluster_size.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/drivers/s390/block/scm_blk_cluster.c b/drivers/s390/block/scm_blk_cluster.c
index f4bb61b0cea1..c0d102e3a48b 100644
--- a/drivers/s390/block/scm_blk_cluster.c
+++ b/drivers/s390/block/scm_blk_cluster.c
@@ -223,6 +223,8 @@ void scm_cluster_request_irq(struct scm_request *scmrq)
 
 bool scm_cluster_size_valid(void)
 {
-	return write_cluster_size == 0 || write_cluster_size == 32 ||
-		write_cluster_size == 64 || write_cluster_size == 128;
+	if (write_cluster_size == 1 || write_cluster_size > 128)
+		return false;
+
+	return !(write_cluster_size & (write_cluster_size - 1));
 }