[PATCH 2/2] clk: pxa: fix pxa2xx_determine_rate return

From: Arnd Bergmann
Date: Tue Nov 08 2016 - 09:51:07 EST


The new pxa2xx_determine_rate() function seems lacking in a few
regards:

- For an exact match or no match at all, the rate is uninitialized
as reported by gcc -Wmaybe-unintialized:
drivers/clk/pxa/clk-pxa.c: In function 'pxa2xx_determine_rate':
drivers/clk/pxa/clk-pxa.c:243:5: error: 'rate' may be used uninitialized in this function

- If we get a non-exact match, the req->rate output is never set
to the actual rate but remains at the requested rate.

- We should not attempt to print a rate if none could be found

This rewrites the logic accordingly.

Fixes: 9fe694295098 ("clk: pxa: transfer CPU clock setting from pxa2xx-cpufreq")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/clk/pxa/clk-pxa.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/pxa/clk-pxa.c b/drivers/clk/pxa/clk-pxa.c
index 50fb9d0ea58d..c423b064c753 100644
--- a/drivers/clk/pxa/clk-pxa.c
+++ b/drivers/clk/pxa/clk-pxa.c
@@ -211,7 +211,7 @@ void pxa2xx_cpll_change(struct pxa2xx_freq *freq,
int pxa2xx_determine_rate(struct clk_rate_request *req,
struct pxa2xx_freq *freqs, int nb_freqs)
{
- int i, closest_below = -1, closest_above = -1, ret = 0;
+ int i, closest_below = -1, closest_above = -1;
unsigned long rate;

for (i = 0; i < nb_freqs; i++) {
@@ -230,18 +230,19 @@ int pxa2xx_determine_rate(struct clk_rate_request *req,

req->best_parent_hw = NULL;

- if (i < nb_freqs)
- ret = 0;
- else if (closest_below >= 0)
+ if (i < nb_freqs) {
+ rate = req->rate;
+ } else if (closest_below >= 0) {
rate = freqs[closest_below].cpll;
- else if (closest_above >= 0)
+ } else if (closest_above >= 0) {
rate = freqs[closest_above].cpll;
- else
- ret = -EINVAL;
+ } else {
+ pr_debug("%s(rate=%lu) no match\n", __func__, req->rate);
+ return -EINVAL;
+ }

- pr_debug("%s(rate=%lu) rate=%lu: %d\n", __func__, req->rate, rate, ret);
- if (!rate)
- req->rate = rate;
+ pr_debug("%s(rate=%lu) rate=%lu\n", __func__, req->rate, rate);
+ req->rate = rate;

- return ret;
+ return 0;
}
--
2.9.0