Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755708AbZJCMJ6 (ORCPT ); Sat, 3 Oct 2009 08:09:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755153AbZJCMJ5 (ORCPT ); Sat, 3 Oct 2009 08:09:57 -0400 Received: from smtp-out003.kontent.com ([81.88.40.217]:46798 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754944AbZJCMJ4 convert rfc822-to-8bit (ORCPT ); Sat, 3 Oct 2009 08:09:56 -0400 From: Oliver Neukum To: Johan Hovold Subject: Re: [PATCH] USB: ftdi_sio: Remove tty->low_latency. Date: Sat, 3 Oct 2009 14:11:40 +0200 User-Agent: KMail/1.10.3 (Linux/2.6.31-rc9-0.1-default; KDE/4.1.3; x86_64; ; ) Cc: Alan Cox , "Eric W. Biederman" , "Greg Kroah-Hartman" , Michael Trimarchi , linux-usb@vger.kernel.org, Andrew Morton , linux-kernel@vger.kernel.org References: <20090924154023.GA27480@localhost> <20091002173308.6158d734@lxorguk.ukuu.org.uk> <20091003114229.GB605@localhost> In-Reply-To: <20091003114229.GB605@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200910031411.41543.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 46 Am Samstag, 3. Oktober 2009 13:42:29 schrieb Johan Hovold: > +???????spin_lock_irqsave(&port->lock, flags); > +???????if (!port->throttled) { > +???????????????spin_unlock_irqrestore(&port->lock, flags); > +???????????????ftdi_submit_read_urb(port, GFP_ATOMIC); > +???????} else > +???????????????spin_unlock_irqrestore(&port->lock, flags); > +} > ? > ?static void ftdi_break_ctl(struct tty_struct *tty, int break_state) > ?{ > @@ -2605,33 +2467,30 @@ static int ftdi_ioctl(struct tty_struct *tty, > struct file *file, static void ftdi_throttle(struct tty_struct *tty) [..] > +???????spin_lock_irqsave(&port->lock, flags); > +???????port->throttled = 1; > +???????spin_unlock_irqrestore(&port->lock, flags); > ?} > ? > - > -static void ftdi_unthrottle(struct tty_struct *tty) > +void ftdi_unthrottle(struct tty_struct *tty) [..] > +???????spin_lock_irqsave(&port->lock, flags); > +???????was_throttled = port->throttled; > +???????port->throttled = 0; > +???????spin_unlock_irqrestore(&port->lock, flags); > ? > -???????if (actually_throttled) > -???????????????schedule_delayed_work(&priv->rx_work, 0); > +???????if (was_throttled && !test_bit(ASYNCB_CLOSING, &port->port.flags)) > +???????????????ftdi_submit_read_urb(port, GFP_KERNEL); > ?} This unfortunately is incorrect. If an unthrottling happens before the read callback runs you submit a running URB. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/