From: Johan Hovold <jhovold@gmail.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Johan Hovold <jhovold@gmail.com>,
Michael Trimarchi <trimarchi@gandalf.sssup.it>,
Oliver Neukum <oliver@neukum.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
linux-usb@vger.kernel.org, Alan Cox <alan@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: ftdi_sio: Remove tty->low_latency.
Date: Wed, 30 Sep 2009 11:05:41 +0200 [thread overview]
Message-ID: <20090930090541.GA13263@localhost> (raw)
In-Reply-To: <20090929235232.1ae6c63b@lxorguk.ukuu.org.uk>
On Tue, Sep 29, 2009 at 11:52:32PM +0100, Alan Cox wrote:
> > As it stands today ftdi_sio does indeed call tty_flip_buffer_push from
> > interrupt context with low_latency set and that is obviously incorrect,
> > right?
>
> It seems to do it from a work queue - or did I miss a case ?
The function used for deferred work is actually called directly from
ftdi_read_bulk_callback:
ftdi_process_read(&priv->rx_work.work);
It only gets scheduled on the work queue when unthrottled (or if
tty_buffer_request_room(tty, length) < length before serial_throttle is
called).
So basically, unless throttled, it is always called from interrupt
context.
/Johan
next prev parent reply other threads:[~2009-09-30 9:05 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-24 15:40 [PATCH] USB: ftdi_sio: Remove tty->low_latency Johan Hovold
2009-09-24 19:03 ` Oliver Neukum
2009-09-24 19:21 ` Alan Cox
2009-09-24 21:15 ` Johan Hovold
2009-09-25 17:46 ` Michael Trimarchi
2009-09-29 14:55 ` Johan Hovold
2009-09-29 22:52 ` Alan Cox
2009-09-30 6:33 ` Michael Trimarchi
2009-09-30 9:05 ` Johan Hovold [this message]
2009-10-02 2:52 ` Eric W. Biederman
2009-10-02 8:47 ` Johan Hovold
2009-10-02 16:33 ` Alan Cox
2009-10-02 22:29 ` Eric W. Biederman
2009-10-03 10:21 ` Johan Hovold
2009-10-02 23:00 ` Eric W. Biederman
2009-10-03 13:09 ` Alan Cox
2009-10-03 23:51 ` Eric W. Biederman
2009-11-17 18:35 ` Eric W. Biederman
2009-11-17 18:41 ` Oliver Neukum
2009-11-17 18:56 ` Eric W. Biederman
2009-11-17 20:05 ` Eric W. Biederman
2009-11-18 1:08 ` Eric W. Biederman
2009-11-18 3:10 ` [PATCH] ftdi_sio: Keep going when write errors are encountered Eric W. Biederman
2009-11-18 3:44 ` Greg KH
2009-10-03 11:42 ` [PATCH] USB: ftdi_sio: Remove tty->low_latency Johan Hovold
2009-10-03 12:11 ` Oliver Neukum
2009-10-03 12:28 ` Johan Hovold
2009-10-03 13:31 ` Oliver Neukum
2009-10-03 14:41 ` Johan Hovold
2009-10-03 13:18 ` Alan Cox
2009-10-03 13:27 ` Oliver Neukum
2009-10-03 14:05 ` Johan Hovold
2009-10-03 16:33 ` Alan Cox
2009-10-03 16:46 ` Johan Hovold
2009-10-04 19:48 ` Johan Hovold
2009-10-04 23:39 ` Eric W. Biederman
2009-10-05 7:01 ` Johan Hovold
2009-10-02 16:59 ` Greg KH
2009-10-02 9:04 ` Alan Cox
2009-10-02 9:53 ` Alan Cox
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