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From: Michael Ellerman <mpe@ellerman.id.au>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hans de Goede <hdegoede@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Revert "console: don't prefer first registered if DT specifies stdout-path"
In-Reply-To: <20161104121135.4780-2-hdegoede@redhat.com>
References: <20161104121135.4780-1-hdegoede@redhat.com> <20161104121135.4780-2-hdegoede@redhat.com>
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Date: Tue, 08 Nov 2016 11:46:35 +1100
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Hans de Goede <hdegoede@redhat.com> writes:

> This reverts commit 05fd007e4629 ("console: don't prefer first registered
> if DT specifies stdout-path").
>
> The reverted commit changes existing behavior on which many ARM boards
> rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have
> both a video output and a serial console. Depending on whether the user
> is using the device as a more regular computer; or as a headless device
> we need to have the console on either one or the other.
>
> Many users rely on the kernel behavior of the console being present on
> both outputs, before the reverted commit the console setup with no
> console= kernel arguments on an ARM board which sets stdout-path in dt
> would look like this:
>
> [root@localhost ~]# cat /proc/consoles
> ttyS0                -W- (EC p a)    4:64
> tty0                 -WU (E  p  )    4:1
>
> Where as after the reverted commit, it looks like this:
>
> [root@localhost ~]# cat /proc/consoles
> ttyS0                -W- (EC p a)    4:64
>
> This commit reverts commit 05fd007e4629 ("console: don't prefer first
> registered if DT specifies stdout-path") restoring the original behavior.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

This is also breaking various powerpc systems.

Linus can you please merge this revert for 4.9 ?

cheers