From: Hans-Joachim Picht <hpicht@redhat.com>
Date: Fri, 16 Nov 2007 13:58:12 +0100
Subject: [s390] qdio: time calculation is wrong
Message-id: 20071116125812.GS6053@redhat.com
O-Subject: [RHEL5 U2 PATCH 11/14] s390 - qdio: Time calculation is wrong.
Bugzilla: 360631

Description
============

Time calculation in qdio_get_micros does not return microseconds as expected.
The return value of get_clock is shifted by 10, which does not return
microseconds.

The problem is fixed using value 12 for shift operation to get microseconds.

Bugzilla
=========

BZ 360631
https://bugzilla.redhat.com/show_bug.cgi?id=360631

Upstream status of the patch:
=============================
Patch is upstream
http://readlist.com/lists/vger.kernel.org/linux-kernel/50/252471.html

Test status:
============
Kernel with patch was built and successfully tested

Please ACK.

With best regards,

Hans

diff --git a/drivers/s390/cio/qdio.c b/drivers/s390/cio/qdio.c
index 280e6ff..ad672ac 100644
--- a/drivers/s390/cio/qdio.c
+++ b/drivers/s390/cio/qdio.c
@@ -139,7 +139,7 @@ static inline void qdio_perf_stat_dec(atomic_t *count)
 static inline __u64 
 qdio_get_micros(void)
 {
-        return (get_clock() >> 10); /* time>>12 is microseconds */
+        return (get_clock() >> 12); /* time>>12 is microseconds */
 }
 
 /*