From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 2/2] gpio: gpiolib: set gpiochip_remove retval to void Date: Fri, 30 May 2014 16:29:22 -0700 Message-ID: <20140530232922.GD25854@kroah.com> References: <20140530094025.3b78301e@canb.auug.org.au> <1401449454-30895-1-git-send-email-berthe.ab@gmail.com> <1401449454-30895-2-git-send-email-berthe.ab@gmail.com> <5388C0F1.90503@gmail.com> <5388CB1B.3090802@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <5388CB1B.3090802@metafoo.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: driverdev-devel-bounces@linuxdriverproject.org To: Lars-Peter Clausen Cc: Linux MIPS Mailing List , David Daney , Linux-sh list , Linus Walleij , platform-driver-x86@vger.kernel.org, "linux-leds@vger.kernel.org" , driverdevel , Alexandre Courbot , patches@opensource.wolfsonmicro.com, linux-samsungsoc@vger.kernel.org, Geert Uytterhoeven , "linux-input@vger.kernel.org" , abdoulaye berthe , spear-devel@list.st.com, "linux-gpio@vger.kernel.org" , m@bues.ch, "linux-arm-kernel@lists.infradead.org" , "netdev@vger.kernel.org" , linux-wireless , "linux-kernel@vger.kernel.org" List-Id: linux-gpio@vger.kernel.org On Fri, May 30, 2014 at 08:16:59PM +0200, Lars-Peter Clausen wrote: > On 05/30/2014 07:33 PM, David Daney wrote: > >On 05/30/2014 04:39 AM, Geert Uytterhoeven wrote: > >>On Fri, May 30, 2014 at 1:30 PM, abdoulaye berthe > >>wrote: > >>>--- a/drivers/gpio/gpiolib.c > >>>+++ b/drivers/gpio/gpiolib.c > >>>@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct > >>>gpio_chip *gpiochip); > >>> * > >>> * A gpio_chip with any GPIOs still requested may not be removed. > >>> */ > >>>-int gpiochip_remove(struct gpio_chip *chip) > >>>+void gpiochip_remove(struct gpio_chip *chip) > >>> { > >>> unsigned long flags; > >>>- int status = 0; > >>> unsigned id; > >>> > >>> acpi_gpiochip_remove(chip); > >>>@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip) > >>> of_gpiochip_remove(chip); > >>> > >>> for (id = 0; id < chip->ngpio; id++) { > >>>- if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { > >>>- status = -EBUSY; > >>>- break; > >>>- } > >>>- } > >>>- if (status == 0) { > >>>- for (id = 0; id < chip->ngpio; id++) > >>>- chip->desc[id].chip = NULL; > >>>- > >>>- list_del(&chip->list); > >>>+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) > >>>+ panic("gpio: removing gpiochip with gpios still > >>>requested\n"); > >> > >>panic? > > > >NACK to the patch for this reason. The strongest thing you should do here > >is WARN. > > > >That said, I am not sure why we need this whole patch set in the first place. > > Well, what currently happens when you remove a device that is a provider of > a gpio_chip which is still in use, is that the kernel crashes. Probably with > a rather cryptic error message. So this patch doesn't really change the > behavior, but makes it more explicit what is actually wrong. And even if you > replace the panic() by a WARN() it will again just crash slightly later. > > This is a design flaw in the GPIO subsystem that needs to be fixed. Then fix the GPIO code properly, don't add a new panic() to the kernel. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sat, 31 May 2014 03:09:00 +0200 (CEST) Received: from out1-smtp.messagingengine.com ([66.111.4.25]:46646 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6820484AbaEaBI61U3fG (ORCPT ); Sat, 31 May 2014 03:08:58 +0200 Received: from compute4.internal (compute4.nyi.mail.srv.osa [10.202.2.44]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id 95DD221061 for ; Fri, 30 May 2014 21:08:56 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute4.internal (MEProxy); Fri, 30 May 2014 21:08:56 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=smtpout; bh=H6hY2X3/GVQAdtxNYu1HS121+zQ=; b=ZI/05HJ9bQDDOFwlT42hHsTRiDYI ckTH4/N4gX7xW7QeFXWQt8IK5MbTnkYnjJIRECTkv/9end2hkn8rANt2VmYElkMH x5hxZEB/t9aoibUZ4Y7ZuQPLHGVpROSJ7cFi/ijm23DC+cC0leV5EKfEzFhl9X+o 0ZopGpc/dW+2BF4= X-Sasl-enc: mG3HOIbkp/gHuYYZ+YnlGJBjY8DMXOaWrduuGzgdh+Yy 1401498536 Received: from localhost (unknown [76.28.255.20]) by mail.messagingengine.com (Postfix) with ESMTPA id 06AFAC00003; Fri, 30 May 2014 21:08:56 -0400 (EDT) Date: Fri, 30 May 2014 16:29:22 -0700 From: Greg KH To: Lars-Peter Clausen Cc: David Daney , platform-driver-x86@vger.kernel.org, Alexandre Courbot , patches@opensource.wolfsonmicro.com, Linux MIPS Mailing List , "netdev@vger.kernel.org" , Linus Walleij , Linux-sh list , linux-wireless , "linux-kernel@vger.kernel.org" , spear-devel@list.st.com, linux-samsungsoc@vger.kernel.org, "linux-gpio@vger.kernel.org" , Geert Uytterhoeven , "linux-leds@vger.kernel.org" , m@bues.ch, "linux-input@vger.kernel.org" , driverdevel , Linux Media Mailing List , "linuxppc-dev@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , abdoulaye berthe Subject: Re: [PATCH 2/2] gpio: gpiolib: set gpiochip_remove retval to void Message-ID: <20140530232922.GD25854@kroah.com> References: <20140530094025.3b78301e@canb.auug.org.au> <1401449454-30895-1-git-send-email-berthe.ab@gmail.com> <1401449454-30895-2-git-send-email-berthe.ab@gmail.com> <5388C0F1.90503@gmail.com> <5388CB1B.3090802@metafoo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5388CB1B.3090802@metafoo.de> User-Agent: Mutt/1.5.23 (2014-03-12) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 40396 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: greg@kroah.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Fri, May 30, 2014 at 08:16:59PM +0200, Lars-Peter Clausen wrote: > On 05/30/2014 07:33 PM, David Daney wrote: > >On 05/30/2014 04:39 AM, Geert Uytterhoeven wrote: > >>On Fri, May 30, 2014 at 1:30 PM, abdoulaye berthe > >>wrote: > >>>--- a/drivers/gpio/gpiolib.c > >>>+++ b/drivers/gpio/gpiolib.c > >>>@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct > >>>gpio_chip *gpiochip); > >>> * > >>> * A gpio_chip with any GPIOs still requested may not be removed. > >>> */ > >>>-int gpiochip_remove(struct gpio_chip *chip) > >>>+void gpiochip_remove(struct gpio_chip *chip) > >>> { > >>> unsigned long flags; > >>>- int status = 0; > >>> unsigned id; > >>> > >>> acpi_gpiochip_remove(chip); > >>>@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip) > >>> of_gpiochip_remove(chip); > >>> > >>> for (id = 0; id < chip->ngpio; id++) { > >>>- if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { > >>>- status = -EBUSY; > >>>- break; > >>>- } > >>>- } > >>>- if (status == 0) { > >>>- for (id = 0; id < chip->ngpio; id++) > >>>- chip->desc[id].chip = NULL; > >>>- > >>>- list_del(&chip->list); > >>>+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) > >>>+ panic("gpio: removing gpiochip with gpios still > >>>requested\n"); > >> > >>panic? > > > >NACK to the patch for this reason. The strongest thing you should do here > >is WARN. > > > >That said, I am not sure why we need this whole patch set in the first place. > > Well, what currently happens when you remove a device that is a provider of > a gpio_chip which is still in use, is that the kernel crashes. Probably with > a rather cryptic error message. So this patch doesn't really change the > behavior, but makes it more explicit what is actually wrong. And even if you > replace the panic() by a WARN() it will again just crash slightly later. > > This is a design flaw in the GPIO subsystem that needs to be fixed. Then fix the GPIO code properly, don't add a new panic() to the kernel. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id C876D1A0008 for ; Sat, 31 May 2014 11:09:00 +1000 (EST) Received: from compute1.internal (compute1.nyi.mail.srv.osa [10.202.2.41]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id A4A9D20A02 for ; Fri, 30 May 2014 21:08:56 -0400 (EDT) Date: Fri, 30 May 2014 16:29:22 -0700 From: Greg KH To: Lars-Peter Clausen Subject: Re: [PATCH 2/2] gpio: gpiolib: set gpiochip_remove retval to void Message-ID: <20140530232922.GD25854@kroah.com> References: <20140530094025.3b78301e@canb.auug.org.au> <1401449454-30895-1-git-send-email-berthe.ab@gmail.com> <1401449454-30895-2-git-send-email-berthe.ab@gmail.com> <5388C0F1.90503@gmail.com> <5388CB1B.3090802@metafoo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <5388CB1B.3090802@metafoo.de> Cc: Linux MIPS Mailing List , David Daney , Linux-sh list , Linus Walleij , platform-driver-x86@vger.kernel.org, "linux-leds@vger.kernel.org" , driverdevel , Alexandre Courbot , patches@opensource.wolfsonmicro.com, linux-samsungsoc@vger.kernel.org, Geert Uytterhoeven , "linux-input@vger.kernel.org" , abdoulaye berthe , spear-devel@list.st.com, "linux-gpio@vger.kernel.org" , m@bues.ch, "linux-arm-kernel@lists.infradead.org" , "netdev@vger.kernel.org" , linux-wireless , "linux-kernel@vger.kernel.org" , Linux Media Mailing List , "linuxppc-dev@lists.ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, May 30, 2014 at 08:16:59PM +0200, Lars-Peter Clausen wrote: > On 05/30/2014 07:33 PM, David Daney wrote: > >On 05/30/2014 04:39 AM, Geert Uytterhoeven wrote: > >>On Fri, May 30, 2014 at 1:30 PM, abdoulaye berthe > >>wrote: > >>>--- a/drivers/gpio/gpiolib.c > >>>+++ b/drivers/gpio/gpiolib.c > >>>@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct > >>>gpio_chip *gpiochip); > >>> * > >>> * A gpio_chip with any GPIOs still requested may not be removed. > >>> */ > >>>-int gpiochip_remove(struct gpio_chip *chip) > >>>+void gpiochip_remove(struct gpio_chip *chip) > >>> { > >>> unsigned long flags; > >>>- int status = 0; > >>> unsigned id; > >>> > >>> acpi_gpiochip_remove(chip); > >>>@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip) > >>> of_gpiochip_remove(chip); > >>> > >>> for (id = 0; id < chip->ngpio; id++) { > >>>- if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { > >>>- status = -EBUSY; > >>>- break; > >>>- } > >>>- } > >>>- if (status == 0) { > >>>- for (id = 0; id < chip->ngpio; id++) > >>>- chip->desc[id].chip = NULL; > >>>- > >>>- list_del(&chip->list); > >>>+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) > >>>+ panic("gpio: removing gpiochip with gpios still > >>>requested\n"); > >> > >>panic? > > > >NACK to the patch for this reason. The strongest thing you should do here > >is WARN. > > > >That said, I am not sure why we need this whole patch set in the first place. > > Well, what currently happens when you remove a device that is a provider of > a gpio_chip which is still in use, is that the kernel crashes. Probably with > a rather cryptic error message. So this patch doesn't really change the > behavior, but makes it more explicit what is actually wrong. And even if you > replace the panic() by a WARN() it will again just crash slightly later. > > This is a design flaw in the GPIO subsystem that needs to be fixed. Then fix the GPIO code properly, don't add a new panic() to the kernel. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 From: greg@kroah.com (Greg KH) Date: Fri, 30 May 2014 16:29:22 -0700 Subject: [PATCH 2/2] gpio: gpiolib: set gpiochip_remove retval to void In-Reply-To: <5388CB1B.3090802@metafoo.de> References: <20140530094025.3b78301e@canb.auug.org.au> <1401449454-30895-1-git-send-email-berthe.ab@gmail.com> <1401449454-30895-2-git-send-email-berthe.ab@gmail.com> <5388C0F1.90503@gmail.com> <5388CB1B.3090802@metafoo.de> Message-ID: <20140530232922.GD25854@kroah.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, May 30, 2014 at 08:16:59PM +0200, Lars-Peter Clausen wrote: > On 05/30/2014 07:33 PM, David Daney wrote: > >On 05/30/2014 04:39 AM, Geert Uytterhoeven wrote: > >>On Fri, May 30, 2014 at 1:30 PM, abdoulaye berthe > >>wrote: > >>>--- a/drivers/gpio/gpiolib.c > >>>+++ b/drivers/gpio/gpiolib.c > >>>@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct > >>>gpio_chip *gpiochip); > >>> * > >>> * A gpio_chip with any GPIOs still requested may not be removed. > >>> */ > >>>-int gpiochip_remove(struct gpio_chip *chip) > >>>+void gpiochip_remove(struct gpio_chip *chip) > >>> { > >>> unsigned long flags; > >>>- int status = 0; > >>> unsigned id; > >>> > >>> acpi_gpiochip_remove(chip); > >>>@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip) > >>> of_gpiochip_remove(chip); > >>> > >>> for (id = 0; id < chip->ngpio; id++) { > >>>- if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { > >>>- status = -EBUSY; > >>>- break; > >>>- } > >>>- } > >>>- if (status == 0) { > >>>- for (id = 0; id < chip->ngpio; id++) > >>>- chip->desc[id].chip = NULL; > >>>- > >>>- list_del(&chip->list); > >>>+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) > >>>+ panic("gpio: removing gpiochip with gpios still > >>>requested\n"); > >> > >>panic? > > > >NACK to the patch for this reason. The strongest thing you should do here > >is WARN. > > > >That said, I am not sure why we need this whole patch set in the first place. > > Well, what currently happens when you remove a device that is a provider of > a gpio_chip which is still in use, is that the kernel crashes. Probably with > a rather cryptic error message. So this patch doesn't really change the > behavior, but makes it more explicit what is actually wrong. And even if you > replace the panic() by a WARN() it will again just crash slightly later. > > This is a design flaw in the GPIO subsystem that needs to be fixed. Then fix the GPIO code properly, don't add a new panic() to the kernel. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 2/2] gpio: gpiolib: set gpiochip_remove retval to void Date: Fri, 30 May 2014 16:29:22 -0700 Message-ID: <20140530232922.GD25854@kroah.com> References: <20140530094025.3b78301e@canb.auug.org.au> <1401449454-30895-1-git-send-email-berthe.ab@gmail.com> <1401449454-30895-2-git-send-email-berthe.ab@gmail.com> <5388C0F1.90503@gmail.com> <5388CB1B.3090802@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Linux MIPS Mailing List , David Daney , Linux-sh list , Linus Walleij , platform-driver-x86@vger.kernel.org, "linux-leds@vger.kernel.org" , driverdevel , Alexandre Courbot , patches@opensource.wolfsonmicro.com, linux-samsungsoc@vger.kernel.org, Geert Uytterhoeven , "linux-input@vger.kernel.org" , abdoulaye berthe , spear-devel@list.st.com, "linux-gpio@vger.kernel.org" , m@bues.ch, "linux-arm-kernel@lists.infradead.org" , "netdev@vger.kernel.org" , linux-wireless , "linux-kernel@vger.kernel.org" Return-path: Content-Disposition: inline In-Reply-To: <5388CB1B.3090802@metafoo.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: driverdev-devel-bounces@linuxdriverproject.org List-Id: netdev.vger.kernel.org On Fri, May 30, 2014 at 08:16:59PM +0200, Lars-Peter Clausen wrote: > On 05/30/2014 07:33 PM, David Daney wrote: > >On 05/30/2014 04:39 AM, Geert Uytterhoeven wrote: > >>On Fri, May 30, 2014 at 1:30 PM, abdoulaye berthe > >>wrote: > >>>--- a/drivers/gpio/gpiolib.c > >>>+++ b/drivers/gpio/gpiolib.c > >>>@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct > >>>gpio_chip *gpiochip); > >>> * > >>> * A gpio_chip with any GPIOs still requested may not be removed. > >>> */ > >>>-int gpiochip_remove(struct gpio_chip *chip) > >>>+void gpiochip_remove(struct gpio_chip *chip) > >>> { > >>> unsigned long flags; > >>>- int status = 0; > >>> unsigned id; > >>> > >>> acpi_gpiochip_remove(chip); > >>>@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip) > >>> of_gpiochip_remove(chip); > >>> > >>> for (id = 0; id < chip->ngpio; id++) { > >>>- if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { > >>>- status = -EBUSY; > >>>- break; > >>>- } > >>>- } > >>>- if (status == 0) { > >>>- for (id = 0; id < chip->ngpio; id++) > >>>- chip->desc[id].chip = NULL; > >>>- > >>>- list_del(&chip->list); > >>>+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) > >>>+ panic("gpio: removing gpiochip with gpios still > >>>requested\n"); > >> > >>panic? > > > >NACK to the patch for this reason. The strongest thing you should do here > >is WARN. > > > >That said, I am not sure why we need this whole patch set in the first place. > > Well, what currently happens when you remove a device that is a provider of > a gpio_chip which is still in use, is that the kernel crashes. Probably with > a rather cryptic error message. So this patch doesn't really change the > behavior, but makes it more explicit what is actually wrong. And even if you > replace the panic() by a WARN() it will again just crash slightly later. > > This is a design flaw in the GPIO subsystem that needs to be fixed. Then fix the GPIO code properly, don't add a new panic() to the kernel. greg k-h