Hi Rhyland, Thanks for the patch.
On Fri, Jun 03, 2016 at 04:30:50PM -0400, Rhyland Klein wrote:
> Add check to power_supply_read_temp() to only use the power_supply
> get_property() callback if the use_cnt is > 0. The use_cnt will
> be incremented at the end of __power_supply_register, so this will
> block to case where get_property can be called before the supply
> is fully registered. This fixes the issue show in the stack below:
>
> [ 1.452598] power_supply_read_temp+0x78/0x80
> [ 1.458680] thermal_zone_get_temp+0x5c/0x11c
> [ 1.464765] thermal_zone_device_update+0x34/0xb4
> [ 1.471195] thermal_zone_device_register+0x87c/0x8cc
> [ 1.477974] __power_supply_register+0x364/0x424
> [ 1.484317] power_supply_register_no_ws+0x10/0x18
> [ 1.490833] bq27xxx_battery_setup+0x10c/0x164
> [ 1.497003] bq27xxx_battery_i2c_probe+0xd0/0x1b0
> [ 1.503435] i2c_device_probe+0x174/0x240
> [ 1.509172] driver_probe_device+0x1fc/0x29c
> [ 1.515167] __driver_attach+0xa4/0xa8
> [ 1.520643] bus_for_each_dev+0x58/0x98
> [ 1.526204] driver_attach+0x20/0x28
> [ 1.531505] bus_add_driver+0x1c8/0x22c
> [ 1.537067] driver_register+0x68/0x108
> [ 1.542630] i2c_register_driver+0x38/0x7c
> [ 1.548457] bq27xxx_battery_i2c_driver_init+0x18/0x20
> [ 1.555321] do_one_initcall+0x38/0x12c
> [ 1.560886] kernel_init_freeable+0x148/0x1ec
> [ 1.566972] kernel_init+0x10/0xfc
> [ 1.572101] ret_from_fork+0x10/0x40
So I guess this should be backported to stable kernels.
> Signed-off-by: Rhyland Klein <rkl...@nvidia.com>
> ---
> drivers/power/power_supply_core.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/power/power_supply_core.c
> b/drivers/power/power_supply_core.c
> index 456987c88baa..070fec621d66 100644
> --- a/drivers/power/power_supply_core.c
> +++ b/drivers/power/power_supply_core.c
> @@ -561,11 +561,16 @@ static int power_supply_read_temp(struct
> thermal_zone_device *tzd,
> {
> struct power_supply *psy;
> union power_supply_propval val;
> - int ret;
> + int ret = 0;
ret should probably be initialized to -EAGAIN to avoid val being
interpreted without get_property() having been called at all?
> WARN_ON(tzd == NULL);
> +
> psy = tzd->devdata;
> - ret = psy->desc->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
> + WARN_ON(atomic_read(&psy->use_cnt) == 0);
I guess the warning can be dropped if error code is properly reported?
> + if (atomic_read(&psy->use_cnt) > 0)
> + ret = psy->desc->get_property(psy, POWER_SUPPLY_PROP_TEMP,
> + &val);
>
> /* Convert tenths of degree Celsius to milli degree Celsius. */
> if (!ret)
-- Sebastian
signature.asc
Description: PGP signature
