linux-kernel - [PATCH] cpupower: mperf monitor: Correct use of ! and &

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Date:	Sat, 5 Jul 2014 20:06:03 +0530
From:	Himangi Saraogi <himangi774@...il.com>
To:	Thomas Renninger <trenn@...e.de>,
	Dominik Brodowski <linux@...inikbrodowski.net>,
	linux-kernel@...r.kernel.org
Cc:	julia.lawall@...6.fr
Subject: [PATCH] cpupower: mperf monitor: Correct use of ! and &

In commit ae91d60ba88ef0bdb1b5e9b2363bd52fc45d2af7, a bug was fixed that
involved converting !x & y to !(x & y).  The code below shows the same
pattern, and thus should perhaps be fixed in the same way.

The Coccinelle semantic patch that makes this change is as follows:

// <smpl>
@@ expression E1,E2; @@
(
  !E1 & !E2
|
- !E1 & E2
+ !(E1 & E2)
)
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@...il.com>
---
This is not tested and clearly changes the semantics, so it is only
something to consider.
 tools/power/cpupower/utils/idle_monitor/mperf_monitor.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
index 5650ab5..90a8c4f 100644
--- a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
+++ b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
@@ -237,7 +237,7 @@ static int init_maxfreq_mode(void)
 	unsigned long long hwcr;
 	unsigned long min;
 
-	if (!cpupower_cpu_info.caps & CPUPOWER_CAP_INV_TSC)
+	if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_INV_TSC))
 		goto use_sysfs;
 
 	if (cpupower_cpu_info.vendor == X86_VENDOR_AMD) {
-- 
1.9.1

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