From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759985Ab2FAOcN (ORCPT ); Fri, 1 Jun 2012 10:32:13 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:40711 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754299Ab2FAOcM (ORCPT ); Fri, 1 Jun 2012 10:32:12 -0400 Date: Fri, 1 Jun 2012 15:34:54 +0100 From: Alan Cox To: Oliver Neukum Cc: Stefani Seibold , linux-kernel@vger.kernel.org, greg@kroah.com, gregkh@linuxfoundation.org, thomas.braunstorfinger@rohde-schwarz.com Subject: Re: [PATCH] add new NRP power meter USB device driver Message-ID: <20120601153454.6f9830a0@pyramind.ukuu.org.uk> In-Reply-To: <201206011616.36284.oneukum@suse.de> References: <1338318858-24144-1-git-send-email-stefani@seibold.net> <201205311020.50076.oneukum@suse.de> <1338456100.6454.82.camel@wall-e> <201206011616.36284.oneukum@suse.de> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 1 Jun 2012 16:16:36 +0200 Oliver Neukum wrote: > Am Donnerstag, 31. Mai 2012, 11:21:40 schrieb Stefani Seibold: > > On Thu, 2012-05-31 at 10:20 +0200, Oliver Neukum wrote: > > > > > > > > > > > > > + if (arg) { > > > > > > + ret = wait_event_interruptible_timeout( > > > > > > + dev->out_running.wait, > > > > > > + list_empty(&dev->out_running.urb_list), > > > > > > + msecs_to_jiffies(arg)); > > > > > > + if (!ret) > > > > > > + return -ETIMEDOUT; > > > > > > + if (ret < 0) > > > > > > + return ret; > > > > > > + return 0; > > > > > > + } else { > > > > > > + return wait_event_interruptible( > > > > > > + dev->out_running.wait, > > > > > > + list_empty(&dev->out_running.urb_list)); > > > > > > + } > > > > > > + break; > > > > > > > > > > This is very ugly. If you need fsync(), then implement it. > > > > > > > > > > > > > fsync() did not meat the requirements, since i need in some case a > > > > timeout for the device. poll() will also not help, since it signals only > > > > that there is space to write. > > > > > > Well, then implement fsync() with interruptible sleep and use a timer > > > in user space. > > > > > > > But this will not solve the problem of older software which is still > > depending on this ioctl. > > Yes. I guess it might be included in a depreated form. However > a sane alternative must be provided. It's a new kernel driver it's not bound to any existing API and we regularly enforce a sane API on drivers being merged so I think the legacy stuff is just "tough" - the out of tree driver will work fine with any legacy code. Alan