Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756328AbZJCN0A (ORCPT ); Sat, 3 Oct 2009 09:26:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756043AbZJCNZ7 (ORCPT ); Sat, 3 Oct 2009 09:25:59 -0400 Received: from smtp-out003.kontent.com ([81.88.40.217]:38099 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754944AbZJCNZ6 convert rfc822-to-8bit (ORCPT ); Sat, 3 Oct 2009 09:25:58 -0400 From: Oliver Neukum To: Alan Cox Subject: Re: [PATCH] USB: ftdi_sio: Remove tty->low_latency. Date: Sat, 3 Oct 2009 15:27:43 +0200 User-Agent: KMail/1.10.3 (Linux/2.6.31-rc9-0.1-default; KDE/4.1.3; x86_64; ; ) Cc: Johan Hovold , "Eric W. Biederman" , "Greg Kroah-Hartman" , Michael Trimarchi , linux-usb@vger.kernel.org, Andrew Morton , linux-kernel@vger.kernel.org References: <20090924154023.GA27480@localhost> <20091003114229.GB605@localhost> <20091003141807.1dc27e4e@lxorguk.ukuu.org.uk> In-Reply-To: <20091003141807.1dc27e4e@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200910031527.43660.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1136 Lines: 29 Am Samstag, 3. Oktober 2009 15:18:07 schrieb Alan Cox: > The generic driver is a very bad example to follow in some areas but > this looks a big improvement. There are some patches reworking the > generic code to use kfifo on the output side which make it vastly better. > Not sure where the relevant google submissions went ? They have been included into rc1. > > -?????spin_lock_irqsave(&priv->rx_lock, flags); > > -?????priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED); > > -?????spin_unlock_irqrestore(&priv->rx_lock, flags); > > +?????spin_lock_irqsave(&port->lock, flags); > > +?????port->throttled = 0; > > +?????spin_unlock_irqrestore(&port->lock, flags); > > If you only have a single bit use the set_bit/clear_bit/test_and_xxx_bit > stuff as it's faster on most boxes I think we cannot do with less than two flags, whose transition has to be atomic here. 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/