From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932082Ab2F0Ktl (ORCPT ); Wed, 27 Jun 2012 06:49:41 -0400 Received: from mail-gg0-f174.google.com ([209.85.161.174]:48790 "EHLO mail-gg0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757189Ab2F0Ktc convert rfc822-to-8bit (ORCPT ); Wed, 27 Jun 2012 06:49:32 -0400 MIME-Version: 1.0 In-Reply-To: <20120627091055.GW31212@elgon.mountain> References: <20120627085800.GA3007@mwanda> <20120627091055.GW31212@elgon.mountain> From: Bryan Wu Date: Wed, 27 Jun 2012 18:49:10 +0800 X-Google-Sender-Auth: sqQ4ISlNEzyCoM3olxhIqPayytM Message-ID: Subject: Re: [patch -resend] leds-lp5523: BUG() in error handling in probe() To: Dan Carpenter Cc: Richard Purdie , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 27, 2012 at 5:10 PM, Dan Carpenter 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 > Signed-off-by: Dan Carpenter > --- > 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 Kernel Developer    +86.186-168-78255 Mobile Canonical Ltd.      www.canonical.com Ubuntu - Linux for human beings | www.ubuntu.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bryan Wu Date: Wed, 27 Jun 2012 10:49:10 +0000 Subject: Re: [patch -resend] leds-lp5523: BUG() in error handling in probe() Message-Id: List-Id: References: <20120627085800.GA3007@mwanda> <20120627091055.GW31212@elgon.mountain> In-Reply-To: <20120627091055.GW31212@elgon.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Dan Carpenter Cc: Richard Purdie , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Wed, Jun 27, 2012 at 5:10 PM, Dan Carpenter w= rote: > Inside the error handling in lp5523_init_led(), there is a place that > calls to led_classdev_unregister(). =A0When we unregister the LED drivers, > it tries to set the brightness to OFF. =A0In 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 > Signed-off-by: Dan Carpenter > --- > I don't have this hardware, so I can't test it. =A0I originally sent this > on Fri, 13 Apr 2012, and that was before Bryan Wu took on the LED > subsystem. =A0Also 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, > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (pdata->led_config[i].led_current =3D 0) > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0continue; > > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 INIT_WORK(&chip->leds[led].brightness_work, > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 lp5523_led_brightness_work); > + > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D lp5523_init_led(&chip->leds[led], = &client->dev, i, pdata); > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (ret) { > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0dev_err(&client->dev, "err= or initializing leds\n"); > @@ -956,9 +959,6 @@ static int __devinit lp5523_probe(struct i2c_client *= client, > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0LP5523_REG_LED_CURRENT= _BASE + chip->leds[led].chan_nr, > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0chip->leds[led].led_cu= rrent); > > - =A0 =A0 =A0 =A0 =A0 =A0 =A0 INIT_WORK(&(chip->leds[led].brightness_work= ), > - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 lp5523_led_brightness_work); > - > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0led++; > =A0 =A0 =A0 =A0} > --=20 Bryan Wu Kernel Developer =A0 =A0+86.186-168-78255 Mobile Canonical Ltd. =A0 =A0 =A0www.canonical.com Ubuntu - Linux for human beings | www.ubuntu.com -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html