The frequency calculation was based on the current(max) frequency of the CPU. However for low frequency, the value used was already the parent frequency divided by a factor of 2.
Instead of using this frequency, this fix directly get the frequency from the parent clock.
Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx") Cc: stable@vger.kernel.org Reported-by: Christian Neubert christian.neubert.86@gmail.com Signed-off-by: Gregory CLEMENT gregory.clement@bootlin.com --- drivers/cpufreq/armada-37xx-cpufreq.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c index ad4463e4266e..a0962463805e 100644 --- a/drivers/cpufreq/armada-37xx-cpufreq.c +++ b/drivers/cpufreq/armada-37xx-cpufreq.c @@ -373,11 +373,11 @@ static int __init armada37xx_cpufreq_driver_init(void) struct armada_37xx_dvfs *dvfs; struct platform_device *pdev; unsigned long freq; - unsigned int cur_frequency; + unsigned int cur_frequency, base_frequency; struct regmap *nb_pm_base, *avs_base; struct device *cpu_dev; int load_lvl, ret; - struct clk *clk; + struct clk *clk, *parent;
nb_pm_base = syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm"); @@ -413,6 +413,22 @@ static int __init armada37xx_cpufreq_driver_init(void) return PTR_ERR(clk); }
+ parent = clk_get_parent(clk); + if (IS_ERR(parent)) { + dev_err(cpu_dev, "Cannot get parent clock for CPU0\n"); + clk_put(clk); + return PTR_ERR(parent); + } + + /* Get parent CPU frequency */ + base_frequency = clk_get_rate(parent); + + if (!base_frequency) { + dev_err(cpu_dev, "Failed to get parent clock rate for CPU\n"); + clk_put(clk); + return -EINVAL; + } + /* Get nominal (current) CPU frequency */ cur_frequency = clk_get_rate(clk); if (!cur_frequency) { @@ -445,7 +461,7 @@ static int __init armada37xx_cpufreq_driver_init(void) for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR; load_lvl++) { unsigned long u_volt = avs_map[dvfs->avs[load_lvl]] * 1000; - freq = cur_frequency / dvfs->divider[load_lvl]; + freq = base_frequency / dvfs->divider[load_lvl]; ret = dev_pm_opp_add(cpu_dev, freq, u_volt); if (ret) goto remove_opp;