Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148AbaAPCaG (ORCPT ); Wed, 15 Jan 2014 21:30:06 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46241 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751314AbaAPCaB (ORCPT ); Wed, 15 Jan 2014 21:30:01 -0500 Date: Wed, 15 Jan 2014 18:30:40 -0800 From: Greg KH To: Hartley Sweeten Cc: Chase Southwood , "devel@driverdev.osuosl.org" , "abbotti@mev.co.uk" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v4] Staging: comedi: convert while loop to timeout in ni_mio_common.c Message-ID: <20140116023040.GB31275@kroah.com> References: <1389669228-15090-1-git-send-email-chase.southwood@yahoo.com> <1389745385-27146-1-git-send-email-chase.southwood@yahoo.com> <20140115035849.GA13127@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 15, 2014 at 06:29:21PM +0000, Hartley Sweeten wrote: > On Tuesday, January 14, 2014 8:59 PM, Greg KH wrote: > > Sleep for at least 10, as I think that's the smallest time delay you can > > sleep for anyway (meaning it will be that long no matter what number you > > put there less than 10, depending on the hardware used of course.) > > A bit off topic here but I have a somewhat related question about timeouts. > > There are a number of comedi drivers that do a "wait for end-of-conversion" > as part of the (*insn_read) for an analog input subdevice or (*insn_write) for > an analog output subdevice. These functions return an errno if a timeout occurs. > > Currently either -ETIME or -ETIMEDOUT is returned. This errno ends up getting > returned to the user as the result of the unlocked_ioctl file operation. What is > the more appropriate errno? Or is there is better one that should be used? I think they should all be -ETIMEDOUT, -ETIME is used for something else, and shouldn't be sent to userspace as I don't think it knows what to do with it. thanks, greg k-h -- 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/