From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
David Airlie <airlied@linux.ie>,
David Miller <davem@davemloft.net>,
Fenghua Yu <fenghua.yu@intel.com>,
Greg Kroah-Hartman <gregkh@suse.de>,
Jason Wessel <jason.wessel@windriver.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Russell King <linux@arm.linux.org.uk>,
Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH 1/3] Input: sysrq - drop tty argument from sysrq ops handlers
Date: Wed, 04 Aug 2010 18:33:50 +1000 [thread overview]
Message-ID: <1280910830.1902.144.camel@pasglop> (raw)
In-Reply-To: <20100804075900.30647.46910.stgit@localhost.localdomain>
On Wed, 2010-08-04 at 00:59 -0700, Dmitry Torokhov wrote:
> Noone is using tty argument so let's get rid of it.
While talking about sysrq...
I noticed that serial drivers call sysrq with the uart lock held.
I've seen deadlocks caused by that, for example, when entering the
debugger, it waits forever for a CPU which is itself waiting on the UART
lock.
I have a patch to drop the lock in serial_core.h, I'll post that
tomorrow hopefully, just checking if there's any objection there ? The
serial drivers might need to be audited a bit to make sure they cope
with the lock being dropped and re-acquired around the sysrq call.
Cheers,
Ben.
next prev parent reply other threads:[~2010-08-04 8:34 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-04 7:58 [PATCH 0/3] SysRq: do not pass tty argument around Dmitry Torokhov
2010-08-04 7:59 ` [PATCH 1/3] Input: sysrq - drop tty argument from sysrq ops handlers Dmitry Torokhov
2010-08-04 8:33 ` Benjamin Herrenschmidt [this message]
2010-08-04 9:09 ` Alan Cox
2010-08-05 1:59 ` Benjamin Herrenschmidt
2010-08-04 12:03 ` Jason Wessel
2010-08-05 2:03 ` Benjamin Herrenschmidt
2010-08-04 7:59 ` [PATCH 2/3] Input: sysrq - drop tty argument form handle_sysrq() Dmitry Torokhov
2010-08-04 11:25 ` Jason Wessel
2010-08-04 7:59 ` [PATCH 3/3] USB: drop tty argument from usb_serial_handle_sysrq_char() Dmitry Torokhov
2010-08-04 11:25 ` Jason Wessel
2010-08-04 9:11 ` [PATCH 0/3] SysRq: do not pass tty argument around Alan Cox
2010-08-04 19:44 ` Greg KH
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=1280910830.1902.144.camel@pasglop \
--to=benh@kernel.crashing.org \
--cc=airlied@linux.ie \
--cc=davem@davemloft.net \
--cc=dmitry.torokhov@gmail.com \
--cc=fenghua.yu@intel.com \
--cc=gregkh@suse.de \
--cc=jason.wessel@windriver.com \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=schwidefsky@de.ibm.com \
--cc=tony.luck@intel.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.