[PATCH v2 3/3] ARM: da850: fix da850_set_pll0rate()

From: Bartosz Golaszewski
Date: Fri Dec 02 2016 - 10:39:41 EST


This function is broken - its second argument is an index to the freq
table, not the requested clock rate in Hz. It leads to an oops when
called from clk_set_rate() since this argument isn't bounds checked
either.

Fix it by iterating over the array of supported frequencies and
selecting a one that matches or returning -EINVAL for unsupported
rates.

Also: update the davinci cpufreq driver. It's the only user of this
clock and currently it passes the cpufreq table index to
clk_set_rate(), which is confusing. Make it pass the requested clock
rate in Hz.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
arch/arm/mach-davinci/da850.c | 22 ++++++++++++++++++----
drivers/cpufreq/davinci-cpufreq.c | 2 +-
2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index a55101c..92e3303 100644
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -1179,14 +1179,28 @@ static int da850_set_armrate(struct clk *clk, unsigned long index)
return clk_set_rate(pllclk, index);
}

-static int da850_set_pll0rate(struct clk *clk, unsigned long index)
+static int da850_set_pll0rate(struct clk *clk, unsigned long rate)
{
- unsigned int prediv, mult, postdiv;
- struct da850_opp *opp;
struct pll_data *pll = clk->pll_data;
+ struct cpufreq_frequency_table *freq;
+ unsigned int prediv, mult, postdiv;
+ struct da850_opp *opp = NULL;
int ret;

- opp = (struct da850_opp *) cpufreq_info.freq_table[index].driver_data;
+ for (freq = da850_freq_table;
+ freq->frequency != CPUFREQ_TABLE_END; freq++) {
+ /* requested_rate is in Hz, freq->frequency is in KHz */
+ unsigned long freq_rate = freq->frequency * 1000;
+
+ if (freq_rate == rate) {
+ opp = (struct da850_opp *)freq->driver_data;
+ break;
+ }
+ }
+
+ if (opp == NULL)
+ return -EINVAL;
+
prediv = opp->prediv;
mult = opp->mult;
postdiv = opp->postdiv;
diff --git a/drivers/cpufreq/davinci-cpufreq.c b/drivers/cpufreq/davinci-cpufreq.c
index b95a872..d54a27c 100644
--- a/drivers/cpufreq/davinci-cpufreq.c
+++ b/drivers/cpufreq/davinci-cpufreq.c
@@ -55,7 +55,7 @@ static int davinci_target(struct cpufreq_policy *policy, unsigned int idx)
return ret;
}

- ret = clk_set_rate(armclk, idx);
+ ret = clk_set_rate(armclk, new_freq * 1000);
if (ret)
return ret;

--
2.9.3