[v2,10/13] cpufreq: powernow-k8: Mark 'hi' and 'lo' dummy variables as __always_unused

Message ID 20200715082634.3024816-11-lee.jones@linaro.org
State Accepted
Commit 638b509795a18c88ce391fb94d9191f1abcfe88d
Headers show
Series
  • Rid W=1 warnings in CPUFreq
Related show

Commit Message

Lee Jones July 15, 2020, 8:26 a.m.
if we fail to use a variable, even a dummy ones, then the compiler
complains that it is set but not used.  We know this is fine, so we
set them as __always_unused here to let the compiler know.

Fixes the following W=1 kernel build warning(s):

 drivers/cpufreq/powernow-k8.c: In function ‘pending_bit_stuck’:
 drivers/cpufreq/powernow-k8.c:89:10: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]
 89 | u32 lo, hi;
 | ^~
 drivers/cpufreq/powernow-k8.c: In function ‘core_voltage_pre_transition’:
 drivers/cpufreq/powernow-k8.c:285:14: warning: variable ‘lo’ set but not used [-Wunused-but-set-variable]
 285 | u32 maxvid, lo, rvomult = 1;
 | ^~

Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>
Cc: Dominik Brodowski <linux@brodo.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Paul Devriendt <paul.devriendt@amd.com>
Cc: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 drivers/cpufreq/powernow-k8.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.25.1

Comments

Pavel Machek July 22, 2020, 12:50 p.m. | #1
On Wed 2020-07-15 09:26:31, Lee Jones wrote:
> if we fail to use a variable, even a dummy ones, then the compiler

> complains that it is set but not used.  We know this is fine, so we

> set them as __always_unused here to let the compiler know.

> 

> Fixes the following W=1 kernel build warning(s):

> 

>  drivers/cpufreq/powernow-k8.c: In function ‘pending_bit_stuck’:

>  drivers/cpufreq/powernow-k8.c:89:10: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]

>  89 | u32 lo, hi;

>  | ^~

>  drivers/cpufreq/powernow-k8.c: In function ‘core_voltage_pre_transition’:

>  drivers/cpufreq/powernow-k8.c:285:14: warning: variable ‘lo’ set but not used [-Wunused-but-set-variable]

>  285 | u32 maxvid, lo, rvomult = 1;

>  | ^~

> 

> Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>

> Cc: Dominik Brodowski <linux@brodo.de>


Acked-by: Pavel Machek <pavel@ucw.cz>


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Patch

diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index 3984959eed1d5..0acc9e241cd7d 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -86,7 +86,7 @@  static u32 convert_fid_to_vco_fid(u32 fid)
  */
 static int pending_bit_stuck(void)
 {
-	u32 lo, hi;
+	u32 lo, hi __always_unused;
 
 	rdmsr(MSR_FIDVID_STATUS, lo, hi);
 	return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
@@ -282,7 +282,7 @@  static int core_voltage_pre_transition(struct powernow_k8_data *data,
 {
 	u32 rvosteps = data->rvo;
 	u32 savefid = data->currfid;
-	u32 maxvid, lo, rvomult = 1;
+	u32 maxvid, lo __always_unused, rvomult = 1;
 
 	pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, reqvid 0x%x, rvo 0x%x\n",
 		smp_processor_id(),