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authorViresh Kumar <viresh.kumar@linaro.org>2016-02-15 05:51:53 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-02-15 22:55:35 +0100
commitc88c395f4a6485f23f81e385c79945d68bcd5c5d (patch)
tree09bb9a06bfc96f42b85ae87b38d852ed7d3043b8 /drivers/base
parentPM / OPP: Fix NULL pointer dereference crash when disabling OPPs (diff)
downloadlinux-c88c395f4a6485f23f81e385c79945d68bcd5c5d.tar.xz
linux-c88c395f4a6485f23f81e385c79945d68bcd5c5d.zip
PM / OPP: Initialize u_volt_min/max to a valid value
We kept u_volt_min/max initialized to 0, when only the target voltage is present in DT, instead of the target/min/max triplet. This didn't go well with the regulator framework, as on few calls the min voltage was set to target and max was set to 0 and so resulted in a kernel crash like below: kernel BUG at ../drivers/regulator/core.c:216! [<c0684af4>] (regulator_check_voltage) from [<c06857ac>] (regulator_set_voltage_unlocked+0x58/0x230) [<c06857ac>] (regulator_set_voltage_unlocked) from [<c06859ac>] (regulator_set_voltage+0x28/0x54) [<c06859ac>] (regulator_set_voltage) from [<c0775b28>] (_set_opp_voltage+0x30/0x98) [<c0775b28>] (_set_opp_voltage) from [<c0776630>] (dev_pm_opp_set_rate+0xf0/0x28c) [<c0776630>] (dev_pm_opp_set_rate) from [<c096f784>] (__cpufreq_driver_target+0x184/0x2b4) [<c096f784>] (__cpufreq_driver_target) from [<c0973760>] (dbs_check_cpu+0x1b0/0x1f4) [<c0973760>] (dbs_check_cpu) from [<c0973f30>] (cpufreq_governor_dbs+0x324/0x5c4) [<c0973f30>] (cpufreq_governor_dbs) from [<c0970958>] (__cpufreq_governor+0xe4/0x1ec) [<c0970958>] (__cpufreq_governor) from [<c09711e0>] (cpufreq_init_policy+0x64/0x8c) [<c09711e0>] (cpufreq_init_policy) from [<c09718cc>] (cpufreq_online+0x2fc/0x708) [<c09718cc>] (cpufreq_online) from [<c0765ff0>] (subsys_interface_register+0x94/0xd8) [<c0765ff0>] (subsys_interface_register) from [<c0970530>] (cpufreq_register_driver+0x14c/0x19c) [<c0970530>] (cpufreq_register_driver) from [<c09746dc>] (dt_cpufreq_probe+0x70/0xec) [<c09746dc>] (dt_cpufreq_probe) from [<c076907c>] (platform_drv_probe+0x4c/0xb0) [<c076907c>] (platform_drv_probe) from [<c07678e0>] (driver_probe_device+0x214/0x2c0) [<c07678e0>] (driver_probe_device) from [<c0767a18>] (__driver_attach+0x8c/0x90) [<c0767a18>] (__driver_attach) from [<c0765c2c>] (bus_for_each_dev+0x68/0x9c) [<c0765c2c>] (bus_for_each_dev) from [<c0766d78>] (bus_add_driver+0x1a0/0x218) [<c0766d78>] (bus_add_driver) from [<c076810c>] (driver_register+0x78/0xf8) [<c076810c>] (driver_register) from [<c0301d74>] (do_one_initcall+0x90/0x1d8) [<c0301d74>] (do_one_initcall) from [<c1100e14>] (kernel_init_freeable+0x15c/0x1fc) [<c1100e14>] (kernel_init_freeable) from [<c0b27a0c>] (kernel_init+0x8/0xf0) [<c0b27a0c>] (kernel_init) from [<c0307d78>] (ret_from_fork+0x14/0x3c) Code: e1550004 baffffeb e3a00000 e8bd8070 (e7f001f2) Fix that by initializing u_volt_min/max to the target voltage in such cases. Reported-and-tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Fixes: 274659029c9d (PM / OPP: Add support to parse "operating-points-v2" bindings) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/opp/core.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index d7cd4e265766..19fd7e7a3969 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -1157,8 +1157,14 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
}
opp->u_volt = microvolt[0];
- opp->u_volt_min = microvolt[1];
- opp->u_volt_max = microvolt[2];
+
+ if (count == 1) {
+ opp->u_volt_min = opp->u_volt;
+ opp->u_volt_max = opp->u_volt;
+ } else {
+ opp->u_volt_min = microvolt[1];
+ opp->u_volt_max = microvolt[2];
+ }
/* Search for "opp-microamp-<name>" */
prop = NULL;