From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:42346 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752989AbbFFUHO (ORCPT ); Sat, 6 Jun 2015 16:07:14 -0400 Message-ID: <55736100.9090408@kernel.org> Date: Sat, 06 Jun 2015 22:07:12 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen , Hartmut Knaack , Peter Meerwald CC: linux-iio@vger.kernel.org Subject: Re: [PATCH 3/3] iio: Require strict scan mask matching in hardware mode References: <1432916062-15195-1-git-send-email-lars@metafoo.de> <1432916062-15195-4-git-send-email-lars@metafoo.de> <556C3546.4020300@kernel.org> <556F3720.80504@metafoo.de> In-Reply-To: <556F3720.80504@metafoo.de> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 06/03/2015 06:19 PM, Lars-Peter Clausen wrote: > On 06/01/2015 12:34 PM, Jonathan Cameron wrote: >> On 29/05/15 17:14, Lars-Peter Clausen wrote: >>> In hardware mode we can not use the software demuxer, this means that >>> the >>> selected scan mask needs to match one of the available scan masks >>> exactly. >>> >>> It also means that all attached buffers need to use the same scan mask. >>> Given that when operating in hardware mode there is typically only a >>> single >>> buffer attached to the device this not an issue. Add a sanity check >>> to make >>> sure that only a single buffer is attached in hardware mode >>> nevertheless. >>> >> That pretty much sums up why devices supporting only hardware buffers >> are probably not going to be a long term feature! >> Mind you for fast devices we may want to allow forced bypassing of the >> demux (i.e. a hardware buffer). >> >> Out of curiosity is this series a precursor to another hardware buffered >> device or just a useful intellectual exercise? > > It's all for real hardware and I'm already using it in some projects. > E.g. one thing I'm working on is adding optional DMA support for some of > the converters, if DMA is available it will use hardware mode. If no DMA > is available or the consumer wants to run in software triggered mode > fallback to software triggered mode. Cool. Looking forward to seeing the use cases! > > - Lars > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html