On Wed, Jun 27, 2012 at 06:49:10PM +0800, Bryan Wu wrote:
> 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?
>
Sorry I should have CC'd Matt on this. I think it's something he
is working on at the University of Wisconsin. That's all I know.
regards,
dan carpenter
> -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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