From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Petr Mladek <pmladek@suse.com>,
Alper Nebi Yasak <alpernebiyasak@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
linux-serial@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Arvind Sankar <nivedita@alum.mit.edu>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Biggers <ebiggers@google.com>,
Feng Tang <feng.tang@intel.com>,
Grzegorz Halat <ghalat@redhat.com>,
Lukas Wunner <lukas@wunner.de>, Nicolas Pitre <nico@fluxnic.net>,
Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [RFC PATCH v2 0/3] Prefer working VT console over SPCR and device-tree chosen stdout-path
Date: Thu, 14 May 2020 08:22:33 +1000 [thread overview]
Message-ID: <2b67927057455bc91310f88a1952f808339f14cb.camel@kernel.crashing.org> (raw)
In-Reply-To: <20200513143755.GM17734@linux-b0ei>
On Wed, 2020-05-13 at 16:37 +0200, Petr Mladek wrote:
> The only common rules are:
>
> + The last console on the command line should always be the
> preferred one when defined.
>
> + Consoles defined by the device (SPCR, device tree) are used
> when there is no commandline.
With the exception that on x86, SPCR is only used for early_con, we
don't do add_preferred_console() at all for it.
I sort-of understand why... the track record on BIOS quality out there
being what it is, I could see this causing a number of systems start
sending the console to a non-existent or non-wired serial port instead
of the tty/gpu because the BIOS leave SPCR set/enabled for no reason.
It may or may not be the case in practice but I don't see how we can
figure that out without either a large campain of data collection from
tons of systems (which will miss plenty) or just taking the chance &
breaking people and see who screams :-)
Cheers,
Ben.
next prev parent reply other threads:[~2020-05-13 22:24 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 16:14 [RFC PATCH v2 0/3] Prefer working VT console over SPCR and device-tree chosen stdout-path Alper Nebi Yasak
2020-04-30 16:14 ` [RFC PATCH v2 1/3] printk: Add function to set console to preferred console's driver Alper Nebi Yasak
2020-04-30 16:46 ` Andy Shevchenko
2020-05-01 1:44 ` Sergey Senozhatsky
2020-05-01 11:48 ` Alper Nebi Yasak
2020-05-13 5:35 ` Sergey Senozhatsky
2020-05-24 10:01 ` Daniel Vetter
2020-04-30 16:14 ` [RFC PATCH v2 2/3] vt: Set as preferred console when a non-dummy backend is bound Alper Nebi Yasak
2020-04-30 16:14 ` [RFC PATCH v2 3/3] printk: Preset tty0 as a pseudo-preferred console Alper Nebi Yasak
2020-04-30 16:44 ` [RFC PATCH v2 0/3] Prefer working VT console over SPCR and device-tree chosen stdout-path Andy Shevchenko
2020-04-30 19:32 ` Alper Nebi Yasak
2020-05-01 1:30 ` Sergey Senozhatsky
2020-05-01 11:08 ` Alper Nebi Yasak
2020-05-01 13:16 ` Andy Shevchenko
2020-05-01 15:07 ` Alper Nebi Yasak
2020-05-13 14:37 ` Petr Mladek
2020-05-13 22:22 ` Benjamin Herrenschmidt [this message]
2020-05-15 19:27 ` Alper Nebi Yasak
2020-05-25 13:04 ` Petr Mladek
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