Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964857Ab3JPSRh (ORCPT ); Wed, 16 Oct 2013 14:17:37 -0400 Received: from mail-bk0-f52.google.com ([209.85.214.52]:35586 "EHLO mail-bk0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934214Ab3JPSRe (ORCPT ); Wed, 16 Oct 2013 14:17:34 -0400 MIME-Version: 1.0 In-Reply-To: <20131016150732.GY2954@intel.com> References: <1381527738-9339-2-git-send-email-youquan.song@intel.com> <20131011133343.GB32689@kroah.com> <20131013152633.GM2954@intel.com> <20131015183142.GA12494@linux-youquan.bj.intel.com> <20131016053857.GV2954@intel.com> <1381912571.29062.135.camel@smile> <20131016075702.GW2954@intel.com> <1381914782.29062.137.camel@smile> <20131016141247.GB17567@kroah.com> <20131016150732.GY2954@intel.com> Date: Wed, 16 Oct 2013 11:17:33 -0700 Message-ID: Subject: Re: [PATCH 1/2] dma: Add interface to calculate data transferred From: Dan Williams To: Vinod Koul Cc: Greg KH , "Shevchenko, Andriy" , Youquan Song , "Song, Youquan" , "Westerberg, Mika" , "linux-kernel@vger.kernel.org" , Dave Jiang Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2228 Lines: 50 On Wed, Oct 16, 2013 at 8:07 AM, Vinod Koul wrote: > On Wed, Oct 16, 2013 at 07:12:47AM -0700, Greg KH wrote: >> On Wed, Oct 16, 2013 at 09:13:20AM +0000, Shevchenko, Andriy wrote: >> > On Wed, 2013-10-16 at 13:27 +0530, Vinod Koul wrote: >> > > On Wed, Oct 16, 2013 at 02:06:30PM +0530, Shevchenko, Andriy wrote: >> > > > On Wed, 2013-10-16 at 11:08 +0530, Vinod Koul wrote: >> > >> > [] >> > >> > > > > Well am going to take it a bit further and ask you why do we need the >> > > > > /sys/class/dma? I have never used it for slave work. >> > > > >> > > > How user (who, f.e., would like to run dmatest) will know names of the >> > > > channels provided? >> > > Ok dmatest requires this, I overlooked that part >> > > >> > > > How could we see what channels of certain dma controller are requested / >> > > > busy from userspace? >> > > But do end user care or need to know about this? >> > >> > The idea is to have some test cases. So, end user probably doesn't >> > really need this. >> >> So could this just be debugfs files instead? > Yes I was thinking on same lines and would agree with you on that. This _really_ > doesn't need sysfs unless Dan some async usage dependent on it. While at it we > can review the fields and remove the ones which are not required... > > Dan, let me know if you are okay with it, I will try to get that done over the > weekend... > Channel naming is the primary use case and several drivers rely on the channel name in their print messages, some for naming resources, and of course dmatest for identifying channels. ioatdma uses it as a parent device for allocating its per-channel 'quickdata' attributes to advertise the capabilities and the ring_size which is useful for determining channel loading and verifying the BIOS configuration. An argument could be made to move the ioatdma attributes to debugfs, but I don't see a clean/worthwhile way of ripping and replacing the channel naming scheme for drivers. -- Dan -- 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/