From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755461AbaJXTni (ORCPT ); Fri, 24 Oct 2014 15:43:38 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:43215 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754745AbaJXTng (ORCPT ); Fri, 24 Oct 2014 15:43:36 -0400 Date: Fri, 24 Oct 2014 14:42:50 -0500 From: Felipe Balbi To: Johan Hovold CC: Felipe Balbi , Russell King , , Subject: Re: [PATCH] ARM: remove redundant irq disable at halt and restart Message-ID: <20141024194250.GF11455@saruman> Reply-To: References: <1414177592-14547-1-git-send-email-johan@kernel.org> <20141024191627.GA11455@saruman> <20141024192111.GC11455@saruman> <20141024192845.GC19377@localhost> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="E69HUUNAyIJqGpVn" Content-Disposition: inline In-Reply-To: <20141024192845.GC19377@localhost> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --E69HUUNAyIJqGpVn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 24, 2014 at 09:28:45PM +0200, Johan Hovold wrote: > On Fri, Oct 24, 2014 at 02:21:11PM -0500, Felipe Balbi wrote: > > On Fri, Oct 24, 2014 at 02:16:27PM -0500, Felipe Balbi wrote: > > > On Fri, Oct 24, 2014 at 09:06:32PM +0200, Johan Hovold wrote: > > > > Remove redundant local_irq_disable() at machine halt and restart. > > > >=20 > > > > Since commit 44424c34049f ("ARM: 7803/1: Fix deadlock scenario with > > > > smp_send_stop()") interrupts are disabled before stopping secondary > > > > CPUs. > > >=20 > > > Assuming this is correct, you should have: > > >=20 > > > Fixes: 44424c3 (ARM: 7803/1: Fix deadlock scenario with smp_send_stop= ()) > > > Cc: # v3.12+ >=20 > It's not a bug. Just a redundant disabling of already disabled > interrupts, something which could possibly lead someone to believe that > interrupts could be re-enabled by the power-off handler. I didn't dig any of this out but I'll assume you did :-) So I withdraw my comment ;-) > > > > diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c > > > > index a35f6ebbd2c2..5663ab57cf07 100644 > > > > --- a/arch/arm/kernel/process.c > > > > +++ b/arch/arm/kernel/process.c > > > > @@ -195,7 +195,6 @@ void machine_halt(void) > > > > local_irq_disable(); > > > > smp_send_stop(); > > > > =20 > > > > - local_irq_disable(); > > > > while (1); > > > > } > > > > =20 > > > > @@ -237,7 +236,6 @@ void machine_restart(char *cmd) > > > > =20 > > > > /* Whoops - the platform was unable to reboot. Tell the user! */ > > > > printk("Reboot failed -- System halted\n"); > > > > - local_irq_disable(); > > >=20 > > > ... but wouldn't this reintroduce the the buck which that commit fixe= d ? > >=20 > > s/buck/bug :-) my fingers have a mind of their own, aparently. >=20 > :) >=20 > No, the interrupts would still be disabled. alright... so far I couldn't find where IRQs are disable before machine_power_off() is called. Starting a do_poweroff(), couldn't find it... Oh well, I'll keep digging. cheers --=20 balbi --E69HUUNAyIJqGpVn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUSqu5AAoJEIaOsuA1yqREpWgP/RLu8bLHDu1TfYg36aXH9OJE rXeXZI6yP27SrzEzIIEoIPrqyrYxcyX0bo+n/T8dnB42jEdSgc/MbMkIAiS0Cu3q TDyzimTUAV/ys9Ngbq7cjhBguruubvAwG8YF/1ZIx3ic+0jaE3ee9OdP4OOeESdG GlQs3oLLfaasUP4XAWzDCJ0HoUAr6a0G+RNoSa0JFY/9cQsAQbOiu7Y19oAA93FC ugyfakc6DchzX6/O6ldo68SoEHlRA/JYiIg67m4vyAU06O7nC5SwOgKAUyu8IZhC DUKsbPMyKX+QHD95rfG2gJN/y7sk+QWti+ebOBcixJBT1QhXbdstCrCKQcl7wTnw 7CHu7UBmcEAkTWlh2qjTCbvXra9f45XwLEOcW+YhR2MrDITSKvf7In2Tb2p6CKNl 9PiZyqR/JBFhwgRb8iJqYAvLxRaLzBAHMLmRsE5tDsoOjPhTLj+TRd5Og5CtWLt2 FCc6yNce5kWngDA9oRoTFoqttEABy8OSA8YxxeLVinJfBo/sGuZSOHWdKvNY9Anz i/5UsJ581ax8/WVl6aambOJVdXypKnG+xIu7br3yw3jQiM9KsRQuMkTQJB7LShAu J2dStRQ1IjrXRENK3QmrdpNTejzvtRnVnwO6Fx/iEqxJlNVg+aM7lCfnXkbdnFNc XkogukZWf1V9NNRvlxWO =rH5H -----END PGP SIGNATURE----- --E69HUUNAyIJqGpVn--