From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: [REGRESSION] "of: Fix premature bootconsole disable with 'stdout-path'" breaks console on tty0 Date: Tue, 17 Mar 2015 16:22:08 -0400 Message-ID: <55088CF0.3050709@hurleysoftware.com> References: <55070544.9010908@redhat.com> <550717A0.3060603@hurleysoftware.com> <55071D0C.2050700@redhat.com> <55071F87.1050706@hurleysoftware.com> <5507227D.8020408@redhat.com> <55075AFD.7000001@hurleysoftware.com> <5507E3E3.5000001@redhat.com> <55082F9F.90909@redhat.com> <55083828.8090705@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55083828.8090705@hurleysoftware.com> Sender: stable-owner@vger.kernel.org To: Rob Herring Cc: Hans de Goede , Grant Likely , Leif Lindholm , Greg Kroah-Hartman , stable , "devicetree@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 03/17/2015 10:20 AM, Peter Hurley wrote: > On 03/17/2015 09:43 AM, Hans de Goede wrote: >> Hi, >> >> On 17-03-15 14:30, Rob Herring wrote: >>> On Tue, Mar 17, 2015 at 3:20 AM, Hans de Goede wrote: >> >> >> >>>> TBH I do not understand why we're even arguing here, AFAICT the behavior >>>> change >>>> is an unwanted side-effect of your patch, so the solution is to rewrite the >>>> patch >>>> so that we get the same end result (not turning off bootconsole-s too early) >>>> without >>>> the unwanted side-effect, and you agreed to work on that ? >>> >>> I intend to revert this if we don't have a fix soon. >>> >>> I think we just need a flag saying we've enabled the earlycon from >>> stdout-path or not and then add the preferred console based on that. I >>> assume with "earlycon" only on the command-line, getting console only >>> on stdout-path is okay. >> >> Yes, if a user explicitly specifies something like "earlycon" on the >> commandline then not automatically getting console output on tty0 is >> fine AFAICT. The use case important for me / distros is when no >> console= (or related) arguments are present on the cmdline at all, >> then the desired behavior is to have console output on tty0 as well >> as on any serial console specified with stdout-path. > > The issues raised by this patch have nothing to do with earlycon. > > 1. PowerPC boot crash - the report with the most troubleshooting info right now > implicates some buffer overflow or console mismanagement triggered by simply > having defined a preferred console. This needs to be figured out regardless, > and this is what I'm working right now. > > 2. Hans' use-case was _already broken_ even before this patch; _any_ driver > that adds a preferred console before the vt console driver will cause > this problem. So again, this needs to be fixed regardless. Rob, You're right; this patch will need to be reverted. I'll send you a revert. Regards, Peter Hurley