Received-SPF: pass (google.com: domain of linux-kernel+bounces-7749-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Feedback-ID: ifd894703:Fastmail
User-Agent: Cyrus-JMAP/3.9.0-alpha0-1364-ga51d5fd3b7-fm-20231219.001-ga51d5fd3
Precedence: bulk
MIME-Version: 1.0
Message-Id: <96543d4c-f08e-443d-9a85-9257fc4f4b6c@app.fastmail.com>
In-Reply-To: <ZYNaFhFp/+q+/Z0Z@alpha.franken.de>
References: <20231029-mips_debug_ll-v1-0-d7a491e8c278@flygoat.com>
 <ZYNaFhFp/+q+/Z0Z@alpha.franken.de>
Date: Thu, 21 Dec 2023 02:21:26 +0000
From: "Jiaxun Yang" <jiaxun.yang@flygoat.com>
To: "Thomas Bogendoerfer" <tsbogend@alpha.franken.de>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/8] MIPS: Unify low-level debugging functionalities
Content-Type: text/plain;charset=utf-8
Content-Transfer-Encoding: quoted-printable


=E5=9C=A82023=E5=B9=B412=E6=9C=8820=E6=97=A5=E5=8D=81=E4=BA=8C=E6=9C=88 =
=E4=B8=8B=E5=8D=889:18=EF=BC=8CThomas Bogendoerfer=E5=86=99=E9=81=93=EF=BC=9A
> On Sun, Oct 29, 2023 at 02:53:01AM +0000, Jiaxun Yang wrote:
>> The plan is to elimiate platform specific early_printk and
>> cps-vec-ns16550 by debug_ll and earlycon.
>
> https://xkcd.com/927/ ?
>
> sorry I don't think that just another new function is good approach.
> Doing this will end up with another method for early debugging and
> all other will stay.

To summarize how are we going to handle low-level debugging after this s=
eries:
1. You are lucky enough that the problem happens after console system in=
itialized
   and you have stack working: go earlycon, or on very few old platforms=
 with platform
   early_printk
2. You are debugging zboot: debug_ll
3. You are debugging SMP bootstrap code like cps-vec: debug_ll
4. Your kernel crashed at the middle of no where before trap_init: debug=
_ll

Thanks
>
> Thomas.
>
> --=20
> Crap can work. Given enough thrust pigs will fly, but it's not necessa=
rily a
> good idea.                                                [ RFC1925, 2=
.3 ]

--=20
- Jiaxun