From: Paul Fulghum <paulkf@microgate.com>
To: "Roland Caßebohm" <roland.cassebohm@VisionSystems.de>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Russell King <rmk+lkml@arm.linux.org.uk>
Subject: Re: Serial driver hangs
Date: Wed, 29 Sep 2004 09:25:51 -0500 [thread overview]
Message-ID: <1096467951.1964.22.camel@deimos.microgate.com> (raw)
In-Reply-To: <200409291607.07493.roland.cassebohm@visionsystems.de>
On Wed, 2004-09-29 at 09:07, Roland Caßebohm wrote:
> I have added a routine to "struct tty_driver" for restarting
> the RX interrupt after TTY_DONT_FLIP bit is cleared in
> read_chan().
If you are using RTS/CTS flow control,
your scheme might prevent data loss if you also
drop RTS (like driver throttle method) when disabling
the rx IRQ and reasserting RTS (unthrottle) when
reenabling the IRQ. Unfortunately, this may interfere
with the line discipline's use of throttle/unthrottle.
> It seems to take to long time in read_chan(). Do you now what
> is the exact reason of locking the filp buffer with the
> TTY_DONT_FLIP flag? For a short look I would say the buffers
> are safe locked by the spinlock tty->read_lock.
I can't identify the reason.
If you feel brave, remove the setting/clearing
of TTY_DONT_FLIP and see what happens.
--
Paul Fulghum
paulkf@microgate.com
next prev parent reply other threads:[~2004-09-29 14:28 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-28 15:34 Serial driver hangs Roland Caßebohm
2004-09-28 21:10 ` Paul Fulghum
2004-09-28 21:16 ` Russell King
2004-09-28 23:03 ` Paul Fulghum
2004-09-28 22:12 ` Alan Cox
2004-09-29 1:12 ` Paul Fulghum
2004-09-29 13:09 ` Roland Caßebohm
2004-09-29 13:17 ` Paul Fulghum
2004-09-29 14:07 ` Roland Caßebohm
2004-09-29 14:25 ` Paul Fulghum [this message]
2004-09-30 16:16 ` Roland Caßebohm
2004-09-30 19:09 ` Paul Fulghum
2004-09-30 18:34 ` Alan Cox
2004-09-30 19:51 ` Paul Fulghum
2004-09-30 19:59 ` Russell King
2004-09-30 20:05 ` Paul Fulghum
2004-09-30 20:30 ` Paul Fulghum
2004-09-30 20:10 ` Alan Cox
2004-09-30 21:25 ` Paul Fulghum
2004-10-01 0:47 ` Paul Fulghum
2004-10-01 15:22 ` Roland Caßebohm
2004-10-01 16:06 ` Paul Fulghum
2004-10-01 20:13 ` Stuart MacDonald
2004-10-01 20:36 ` Paul Fulghum
2004-09-29 14:13 ` Paul Fulghum
2004-10-01 15:25 ` Roland Caßebohm
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=1096467951.1964.22.camel@deimos.microgate.com \
--to=paulkf@microgate.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=rmk+lkml@arm.linux.org.uk \
--cc=roland.cassebohm@VisionSystems.de \
/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