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From: Greg KH <gregkh@suse.de>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Luck <tony.luck@intel.com>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	John Kacur <jkacur@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] serial: revert "Use block_til_ready helper"
Date: Tue, 22 Jun 2010 16:01:13 -0700	[thread overview]
Message-ID: <20100622230113.GB18495@suse.de> (raw)
In-Reply-To: <201006192229.21971.arnd@arndb.de>

On Sat, Jun 19, 2010 at 10:29:21PM +0200, Arnd Bergmann wrote:
> On Saturday 19 June 2010 14:32:04 Arnd Bergmann wrote:
> > > I boot with a "console=uart,io,0x3f8" argument, so I start out using
> > > 8250_early.c. Looks like it switched to 8250.c based on seeing
> > > this:
> > > 
> > > Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> > > 
> > > on the console log.
> > 
> > Good, so it's something I should be able to reproduce on a PC.
> 
> I could reproduce the problem now and bisected it down to a cleanup
> patch that can fortunately get reverted. The symptom that I saw
> is that when I open a serial port for the second time (e.g. starting
> getty and logging in), the output gets garbled, while the first one
> worked fine. This does not rely on the console code at all.
> 
> Original commit message:
>     Our code now rather closely resembles the helper, so switch to it.
> 
> Apparently, the two functions are not really doing the same,
> so revert the commit for now. This includes the addition of
> a tty_unlock()/tty_lock() pair when blocking on the wait queue.
> 
> Greg, do you want to apply this patch on top of the series, or
> do you prefer to get a replacement for the original patch, once
> we know what's wrong with it?

A replacement for the original one might be best if we can figure it
out.

Just let me know what you need me to do.

thanks,

greg k-h

  parent reply	other threads:[~2010-06-22 23:04 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-15 20:59 [PATCH v3 00/10] BKL conversion in tty layer Arnd Bergmann
2010-05-15 20:59 ` [PATCH 01/10] tty: replace BKL with a new tty_lock Arnd Bergmann
2010-05-15 20:59 ` [PATCH 02/10] tty: never hold BTM while getting tty_mutex Arnd Bergmann
2010-05-15 20:59 ` [PATCH 03/10] tty: fix console_sem lock order Arnd Bergmann
2010-05-15 20:59 ` [PATCH 04/10] cdc-acm: remove dead code Arnd Bergmann
2010-05-15 20:59 ` [PATCH 05/10] tty: introduce wait_event_interruptible_tty Arnd Bergmann
2010-05-15 20:59 ` [PATCH 06/10] tty: annotate tty_write_lock Arnd Bergmann
2010-05-15 20:59 ` [PATCH 07/10] tty: reorder ldisc locking Arnd Bergmann
2010-05-15 20:59 ` [PATCH 08/10] tty: untangle locking of wait_until_sent Arnd Bergmann
2010-05-16  3:12   ` Daniel K.
2010-05-15 20:59 ` [PATCH 09/10] tty: remove tty_lock_nested Arnd Bergmann
2010-05-15 20:59 ` [PATCH 10/10] tty: implement BTM as mutex instead of BKL Arnd Bergmann
2010-05-16  3:33   ` Daniel K.
2010-05-16 12:58     ` Arnd Bergmann
2010-05-17 13:41 ` [PATCH v3 00/10] BKL conversion in tty layer Alan Cox
2010-05-17 15:30   ` Greg KH
2010-05-17 18:30     ` Arnd Bergmann
2010-05-18  4:27       ` Greg KH
2010-05-18 21:52         ` Arnd Bergmann
2010-05-19  1:50           ` Greg KH
2010-05-22 13:54             ` Arnd Bergmann
2010-05-17 18:49   ` Arnd Bergmann
2010-06-17 19:13   ` Tony Luck
2010-06-17 19:40     ` Arnd Bergmann
2010-06-17 20:15       ` Tony Luck
2010-06-17 21:48         ` Arnd Bergmann
2010-06-17 22:09           ` Frederic Weisbecker
2010-06-18 12:58             ` [PATCH] tty: avoid recursive BTM in pty_close Arnd Bergmann
2010-06-18 16:21               ` Alan Cox
2010-06-18 16:52                 ` Tony Luck
2010-06-18 18:35                   ` Arnd Bergmann
2010-06-18 20:25                     ` Tony Luck
2010-06-19 12:32                       ` Arnd Bergmann
2010-06-19 20:29                         ` [PATCH] serial: revert "Use block_til_ready helper" Arnd Bergmann
2010-06-19 21:57                           ` Alan Cox
2010-06-20 20:54                             ` Arnd Bergmann
2010-06-21 14:13                               ` Alan Cox
2010-06-21 20:57                                 ` Arnd Bergmann
2010-06-21 20:58                                   ` Arnd Bergmann
2010-06-21 17:11                           ` Tony Luck
2010-06-22 23:01                           ` Greg KH [this message]
2010-06-28 17:17                     ` [PATCH] tty: avoid recursive BTM in pty_close Tony Luck
2010-06-28 19:03                       ` Arnd Bergmann

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