Bug#867259: No usage of ttySx any more

[Karsten <debian@decotrain.de>]

Hello,

I have found the following problem that has been fixed in kernel 4.9.5:

https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.5

commit 1f363639eb30c2a4ef9ff125e2fbfe213d82a2f9
Author: Herbert Xu <herbert@gondor.apana.org.au>
Date:   Sun Dec 11 10:05:49 2016 +0800

    Revert "tty: serial: 8250: add CON_CONSDEV to flags"

    commit 6741f551a0b26479de2532ffa43a366747e6dbf3 upstream.

    This commit needs to be reverted because it prevents people from
    using the serial console as a secondary console with input being
    directed to tty0.

    IOW, if you boot with console=ttyS0 console=tty0 then all kernels
    prior to this commit will produce output on both ttyS0 and tty0
    but input will only be taken from tty0.  With this patch the serial
    console will always be the primary console instead of tty0,
    potentially preventing people from getting into their machines in
    emergency situations.

    Fixes: d03516df8375 ("tty: serial: 8250: add CON_CONSDEV to flags")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


Maybe this is the reason causing the problem in kernel 4.9.0?

Best regards
Karsten