Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754415Ab2FUGet (ORCPT ); Thu, 21 Jun 2012 02:34:49 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:47504 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752190Ab2FUGes (ORCPT ); Thu, 21 Jun 2012 02:34:48 -0400 Message-ID: <4FE2C082.1060302@monstr.eu> Date: Thu, 21 Jun 2012 08:34:42 +0200 From: Michal Simek Reply-To: monstr@monstr.eu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Stephan Linz CC: microblaze-uclinux@itee.uq.edu.au, linux-kernel@vger.kernel.org Subject: Re: [PATCH] microblaze: improve failure handling for GPIO reset References: <1340224597-18282-1-git-send-email-linz@li-pro.net> In-Reply-To: <1340224597-18282-1-git-send-email-linz@li-pro.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2857 Lines: 76 On 06/20/2012 10:36 PM, Stephan Linz wrote: > Early exit from of_platform_reset_gpio_probe() if there > was no GPIO reset line configured. > > Avoid kernel oops in gpio_system_reset(): > > [ 27.413294] Restarting system. > [ 27.415674] Machine restart... > [ 27.418787] Oops: kernel access of bad area, sig: 11 > [ 27.423252] Registers dump: mode=83871D1C > [ 27.427428] r1=00000000, r2=00000000, r3=FFFFFEF8, r4=00000000 > [ 27.433310] r5=C026AED0, r6=00000001, r7=00000068, r8=00000000 > [ 27.439189] r9=C3871DAC, r10=000011A5, r11=00000000, r12=0000000A > [ 27.445318] r13=00000000, r14=0000000F, r15=C00029BC, r16=00000000 > [ 27.451558] r17=C011DE8C, r18=80000115, r19=0000000F, r20=48184ED8 > [ 27.457770] r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD > [ 27.463982] r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000 > [ 27.470208] r29=00000000, r30=00000000, r31=C32D30C0, rPC=C011DE8C > [ 27.476433] msr=000042A2, ear=0000004B, esr=00000872, fsr=342E3732 > > Signed-off-by: Stephan Linz > --- > arch/microblaze/kernel/reset.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c > index 88a0163..7a08071 100644 > --- a/arch/microblaze/kernel/reset.c > +++ b/arch/microblaze/kernel/reset.c > @@ -28,6 +28,7 @@ void of_platform_reset_gpio_probe(void) > if (!gpio_is_valid(handle)) { > printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n", > handle, "reset"); > + return; > } > > ret = gpio_request(handle, "reset"); > @@ -60,7 +61,8 @@ err: > > static void gpio_system_reset(void) > { > - gpio_set_value(handle, 1 - reset_val); > + if (gpio_is_valid(handle)) > + gpio_set_value(handle, 1 - reset_val); > } > #else > #define gpio_system_reset() do {} while (0) > @@ -74,6 +76,7 @@ void machine_restart(char *cmd) > { > printk(KERN_NOTICE "Machine restart...\n"); > gpio_system_reset(); > + printk(KERN_NOTICE "Dump stack on machines without reset line ...\n"); > dump_stack(); > while (1) > ; Your changes looks good. Some weeks ago we have changed this code a little bit too by removing dump_stack() and change printk message to "NO reset GPIO available in the system" or similar. I think we can add these two changes together because truth is that dump_stack didn't give you any useful output. Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/