Re: [PATCH 07/14 v3] bq27x00: Cache battery registers

From: Grazvydas Ignotas
Date: Mon Feb 21 2011 - 16:23:13 EST


On Mon, Feb 21, 2011 at 4:49 PM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
> On 02/21/2011 03:00 PM, Grazvydas Ignotas wrote:
>> It comes from power_supply_changed, probably omitted because
>> queue_work is a tail function of power_supply_changed. It's probably
>> something i2c specific, I could try bisecting it for you if you like,
>> I know it doesn't happen before this series.
>
> Hi
>
> The following patch should hopefully fix the issue.

Indeed it does, everything is working nicely now.
For the whole series:
Tested-by: Grazvydas Ignotas <notasas@xxxxxxxxx>

>
> From 860fc31cef00bd87085100825ddbff82ad601c33 Mon Sep 17 00:00:00 2001
> From: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Date: Mon, 21 Feb 2011 15:34:19 +0100
> Subject: [PATCH] Initialize power_supply changed_work before calling device_add
>
> Calling device_add causes a uevent for that device to be generated.
> The power_supply uevent function calls the drivers get_property function,
> which might causes the driver to update its state, which again might causes
> the driver to call power_supply_changed(). Since the power_supplys
> changed_work has not been initialized at this point the behavior is
> undefined and might result in a OOPS.
>
> This patch fixes the issue by initializing the power_supplys changed_work
> prior to adding the power_supplys device to the device tree.
>
> Reported-by: Grazvydas Ignotas <notasas@xxxxxxxxx>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> ---
>  drivers/power/power_supply_core.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
> index 970f733..329b46b 100644
> --- a/drivers/power/power_supply_core.c
> +++ b/drivers/power/power_supply_core.c
> @@ -171,6 +171,8 @@ int power_supply_register(struct device *parent, struct
> power_supply *psy)
>        dev_set_drvdata(dev, psy);
>        psy->dev = dev;
>
> +       INIT_WORK(&psy->changed_work, power_supply_changed_work);
> +
>        rc = kobject_set_name(&dev->kobj, "%s", psy->name);
>        if (rc)
>                goto kobject_set_name_failed;
> @@ -179,8 +181,6 @@ int power_supply_register(struct device *parent, struct
> power_supply *psy)
>        if (rc)
>                goto device_add_failed;
>
> -       INIT_WORK(&psy->changed_work, power_supply_changed_work);
> -
>        rc = power_supply_create_triggers(psy);
>        if (rc)
>                goto create_triggers_failed;
> --
> 1.7.2.3
>
>
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