linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Petr Mladek <pmladek@suse.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	John Ogness <john.ogness@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Shreyas Joshi <shreyas.joshi@biamp.com>,
	shreyasjoshi15@gmail.com,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>
Subject: [PATCH 0/2] printk/console: Use ttynull when no console is available or wanted
Date: Wed, 11 Nov 2020 14:54:48 +0100	[thread overview]
Message-ID: <20201111135450.11214-1-pmladek@suse.com> (raw)

This is another attempt to solve regression caused by the commit
48021f98130880dd74 ("printk: handle blank console arguments passed in.").

It prevented a crash caused by empty console= parameter. But it caused
performance problems on Chromebooks because they use it to disable
all consoles, see
see https://lore.kernel.org/r/20201006025935.GA597@jagdpanzerIV.localdomain

Solve both problems by using ttynull console driver that was crated
exactly for this purpose.

The 1st patch should prevent the crash for any invalid console name.

The 2nd patch allows to used the ttynull driver also with the widely
used console= and console=null parameters.

Best Regards,
Petr

Petr Mladek (2):
  init/console: Use ttynull as a fallback when there is no console
  printk/console: Allow to disable console output by using console="" or
    console=null

 drivers/tty/Kconfig     | 14 --------------
 drivers/tty/Makefile    |  3 +--
 drivers/tty/ttynull.c   | 18 ++++++++++++++++++
 include/linux/console.h |  3 +++
 init/main.c             | 10 ++++++++--
 kernel/printk/printk.c  |  9 ++++++++-
 6 files changed, 38 insertions(+), 19 deletions(-)

-- 
2.26.2


             reply	other threads:[~2020-11-11 13:55 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-11 13:54 Petr Mladek [this message]
2020-11-11 13:54 ` [PATCH 1/2] init/console: Use ttynull as a fallback when there is no console Petr Mladek
2020-11-11 16:36   ` Greg Kroah-Hartman
2020-11-11 22:52   ` Guenter Roeck
2020-11-11 23:58   ` Sergey Senozhatsky
2020-11-12  0:17   ` Sergey Senozhatsky
2020-11-12  1:45     ` Sergey Senozhatsky
2020-11-16 16:20       ` Petr Mladek
2021-01-06 23:36   ` ARC no console output (was Re: [PATCH 1/2] init/console: Use ttynull as a fallback when there is no console) Vineet Gupta
2021-01-07  9:02     ` John Ogness
2021-01-07 13:14       ` Greg Ungerer
2021-01-07 16:43       ` Vineet Gupta
2021-01-07 17:04         ` Petr Mladek
2021-01-07 17:58           ` Vineet Gupta
2021-01-08  3:48             ` Sergey Senozhatsky
2021-01-08  5:18               ` Vineet Gupta
2021-01-08  9:30                 ` Petr Mladek
2021-01-13 22:07             ` Peter Korsgaard
2021-01-07  9:09     ` Richard Weinberger
2021-01-07 12:48     ` Petr Mladek
2021-01-07 15:27     ` [Buildroot] " Yann E. MORIN
2020-11-11 13:54 ` [PATCH 2/2] printk/console: Allow to disable console output by using console="" or console=null Petr Mladek
2020-11-11 22:52   ` Guenter Roeck
2020-11-11 23:59   ` Sergey Senozhatsky
2020-11-20 14:24 ` [PATCH 0/2] printk/console: Use ttynull when no console is available or wanted Petr Mladek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201111135450.11214-1-pmladek@suse.com \
    --to=pmladek@suse.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=john.ogness@linutronix.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=rostedt@goodmis.org \
    --cc=sergey.senozhatsky.work@gmail.com \
    --cc=sergey.senozhatsky@gmail.com \
    --cc=shreyas.joshi@biamp.com \
    --cc=shreyasjoshi15@gmail.com \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).