omap3 overo boots crash with
Unable to handle kernel NULL pointer dereference at virtual address 00000030
pgd = c0204000
[00000030] *pgd=00000000
Internal error: Oops: 17 [#1] SMP ARM
...
[] (regulator_set_voltage) from [] (_set_opp_voltage+0x34/0x90)
[] (_set_opp_voltage) from [] (dev_pm_opp_set_rate+0x19c/0x288)
[] (dev_pm_opp_set_rate) from [] (__cpufreq_driver_target+0x17c/0x29c)
[] (__cpufreq_driver_target) from [] (dbs_check_cpu+0x19c/0x1e4)
[] (dbs_check_cpu) from [] (cpufreq_governor_dbs+0x308/0x5c4)
[] (cpufreq_governor_dbs) from [] (__cpufreq_governor+0x20c/0x24c)
[] (__cpufreq_governor) from [] (cpufreq_init_policy+0x60/0x8c)
[] (cpufreq_init_policy) from [] (cpufreq_online+0x2cc/0x6d8)
[] (cpufreq_online) from [] (subsys_interface_register+0x80/0xc4)
[] (subsys_interface_register) from [] (cpufreq_register_driver+0x144/0x1a0)
[] (cpufreq_register_driver) from [] (dt_cpufreq_probe+0x64/0xe8)
[] (dt_cpufreq_probe) from [] (platform_drv_probe+0x50/0xb0)
[] (platform_drv_probe) from [] (driver_probe_device+0x1f4/0x2b0)
...
Analysis shows that regulator==NULL in regulator_set_voltage().
Code around _set_opp_voltage() suggests that having no voltage regulator
attached to a CPU clock is valid, so do not attempt to set a voltage
in that case.
Fixes: 6a0712f6f199e ("PM / OPP: Add dev_pm_opp_set_rate()"
Cc: Viresh Kumar <viresh.ku...@linaro.org>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
drivers/base/power/opp/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index d7cd4e265766..82ad5ae72427 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -564,7 +564,7 @@ static int _set_opp_voltage(struct device *dev, struct
regulator *reg,
int ret;
/* Regulator not available for device */
- if (IS_ERR(reg)) {
+ if (IS_ERR_OR_NULL(reg)) {
dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
PTR_ERR(reg));
return 0;
--
2.5.0
