On Wed, Jun 27, 2012 at 5:10 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> Inside the error handling in lp5523_init_led(), there is a place that
> calls to led_classdev_unregister(). When we unregister the LED drivers,
> it tries to set the brightness to OFF. In this driver setting the
> brightness is done through a work queue and the work queue hasn't been
> initialized yet.
>
> The result is that we trigger a WARN_ON() in the __queue_work().
>
> The fix is to move the INIT_WORK() in front of the call to
> lp5523_init_led().
>
Thanks for resending this, I applied this in my for-next branch.
> Matt Renzelmann found this using a bug finding tool.
Just be curious, what's kind of the tool here?
-Bryan
>
> Reported-by: Matt Renzelmann <mjr@xxxxxxxxxxx>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> I don't have this hardware, so I can't test it. I originally sent this
> on Fri, 13 Apr 2012, and that was before Bryan Wu took on the LED
> subsystem. Also when I sent it, the WARN_ON() in __queue_work() was
> a BUG_ON() so I've updated the commit message.
>
> diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
> index 857a3e1..e8a2712 100644
> --- a/drivers/leds/leds-lp5523.c
> +++ b/drivers/leds/leds-lp5523.c
> @@ -943,6 +943,9 @@ static int __devinit lp5523_probe(struct i2c_client *client,
> if (pdata->led_config[i].led_current == 0)
> continue;
>
> + INIT_WORK(&chip->leds[led].brightness_work,
> + lp5523_led_brightness_work);
> +
> ret = lp5523_init_led(&chip->leds[led], &client->dev, i, pdata);
> if (ret) {
> dev_err(&client->dev, "error initializing leds\n");
> @@ -956,9 +959,6 @@ static int __devinit lp5523_probe(struct i2c_client *client,
> LP5523_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
> chip->leds[led].led_current);
>
> - INIT_WORK(&(chip->leds[led].brightness_work),
> - lp5523_led_brightness_work);
> -
> led++;
> }
>
--
Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
Kernel Developer +86.186-168-78255 Mobile
Canonical Ltd. www.canonical.com
Ubuntu - Linux for human beings | www.ubuntu.com
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