[PATCH] cpufreq: cpufreq-dt: avoid uninitialized variable warnings:

From: Arnd Bergmann
Date: Mon Jan 25 2016 - 10:46:42 EST


gcc warns quite a bit about values returned from allocate_resources()
in cpufreq-dt.c:

cpufreq-dt.c: In function 'cpufreq_init':
cpufreq-dt.c:327:6: error: 'cpu_dev' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:197:17: note: 'cpu_dev' was declared here
cpufreq-dt.c:376:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:199:14: note: 'cpu_clk' was declared here
cpufreq-dt.c: In function 'dt_cpufreq_probe':
cpufreq-dt.c:461:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:447:14: note: 'cpu_clk' was declared here

The problem is that it's slightly hard for gcc to follow return
codes across PTR_ERR() calls.
This patch uses explicit assignments to the "ret" variable to make
it easier for gcc to verify that the code is actually correct,
without the need to add a bogus initialization.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/cpufreq/cpufreq-dt.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 9bc37c437874..0ca74d070058 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -142,15 +142,16 @@ static int allocate_resources(int cpu, struct device **cdev,

try_again:
cpu_reg = regulator_get_optional(cpu_dev, reg);
- if (IS_ERR(cpu_reg)) {
+ ret = PTR_ERR_OR_ZERO(cpu_reg);
+ if (ret) {
/*
* If cpu's regulator supply node is present, but regulator is
* not yet registered, we should try defering probe.
*/
- if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
+ if (ret == -EPROBE_DEFER) {
dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
cpu);
- return -EPROBE_DEFER;
+ return ret;
}

/* Try with "cpu-supply" */
@@ -159,18 +160,16 @@ try_again:
goto try_again;
}

- dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n",
- cpu, PTR_ERR(cpu_reg));
+ dev_dbg(cpu_dev, "no regulator for cpu%d: %d\n", cpu, ret);
}

cpu_clk = clk_get(cpu_dev, NULL);
- if (IS_ERR(cpu_clk)) {
+ ret = PTR_ERR_OR_ZERO(cpu_clk);
+ if (ret) {
/* put regulator */
if (!IS_ERR(cpu_reg))
regulator_put(cpu_reg);

- ret = PTR_ERR(cpu_clk);
-
/*
* If cpu's clk node is present, but clock is not yet
* registered, we should try defering probe.
--
2.7.0