Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: Peter Korsgaard <jacmet@gmail.com>
From:   Peter Korsgaard <peter@korsgaard.com>
To:     Vineet Gupta <vgupta@synopsys.com>
Cc:     Petr Mladek <pmladek@suse.com>, linux-arch@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        John Ogness <john.ogness@linutronix.de>,
        Shreyas Joshi <shreyas.joshi@biamp.com>,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        buildroot@busybox.net, arcml <linux-snps-arc@lists.infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        shreyasjoshi15@gmail.com, Guenter Roeck <linux@roeck-us.net>
Subject: Re: ARC no console output (was Re: [PATCH 1/2] init/console: Use ttynull as a fallback when there is no console)
References: <20201111135450.11214-1-pmladek@suse.com>
        <20201111135450.11214-2-pmladek@suse.com>
        <d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com>
        <8735zdm86m.fsf@jogness.linutronix.de>
        <50ade852-c598-6476-1f4b-9a3f8d11d143@synopsys.com>
        <X/c/ONCYz2QQdvOP@alley>
        <466644f5-bed7-caef-9fcd-e66208f65545@synopsys.com>
Date:   Wed, 13 Jan 2021 23:07:45 +0100
In-Reply-To: <466644f5-bed7-caef-9fcd-e66208f65545@synopsys.com> (Vineet
        Gupta's message of "Thu, 7 Jan 2021 09:58:05 -0800")
Message-ID: <87turkfq32.fsf@dell.be.48ers.dk>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

>>>>> "Vineet" == Vineet Gupta <vgupta@synopsys.com> writes:

 > On 1/7/21 9:04 AM, Petr Mladek wrote:
 >> On Thu 2021-01-07 08:43:16, Vineet Gupta wrote:
 >>> Hi John,
 >>> 
 >>> On 1/7/21 1:02 AM, John Ogness wrote:
 >>>> Hi Vineet,
 >>>> 
 >>>> On 2021-01-06, Vineet Gupta <vgupta@synopsys.com> wrote:
 >>>>> This breaks ARC booting (no output on console).
 >>>> 
 >>>> Could you provide the kernel boot arguments that you use? This series is
 >>>> partly about addressing users that have used boot arguments that are
 >>>> technically incorrect (even if had worked). Seeing the boot arguments of
 >>>> users that are not experiencing problems may help to reveal some of the
 >>>> unusual console usages until now.
 >>> 
 >>> 
 >>> Kernel command line: earlycon=uart8250,mmio32,0xf0005000,115200n8
 >>> console=ttyS0,115200n8 debug print-fatal-signals=1
 >> 
 >> This is strange, the problematic patch should use ttynull
 >> only as a fallback. It should not be used when a particular console
 >> is defined on the command line.

 > What happens in my case is console_on_rootfs() doesn't find
 > /dev/console and switching to ttynull. /dev is not present because
 > devtmpfs doesn't automount for initramfs.

But our initramfs/cpio logic ensures that the initramfs has a static
/dev/console device node, so how can that be?

https://git.buildroot.net/buildroot/tree/fs/cpio/cpio.mk#n25

-- 
Bye, Peter Korsgaard