From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756033AbcKKLGB (ORCPT ); Fri, 11 Nov 2016 06:06:01 -0500 Received: from mail-it0-f67.google.com ([209.85.214.67]:35773 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755394AbcKKLF7 (ORCPT ); Fri, 11 Nov 2016 06:05:59 -0500 MIME-Version: 1.0 In-Reply-To: <1478795309.2603.55.camel@synopsys.com> References: <1477670402-23943-1-git-send-email-Eugeniy.Paltsev@synopsys.com> <1478087707.2603.7.camel@synopsys.com> <1478526908.5295.67.camel@linux.intel.com> <1478607771.2603.31.camel@synopsys.com> <1478612190.5295.92.camel@linux.intel.com> <1478795309.2603.55.camel@synopsys.com> From: Andy Shevchenko Date: Fri, 11 Nov 2016 13:05:57 +0200 Message-ID: Subject: Re: [PATCH v3 0/3] dmaengine: DW DMAC: split pdata to hardware properties To: Eugeniy Paltsev Cc: "andriy.shevchenko@linux.intel.com" , "dan.j.williams@intel.com" , "linux-kernel@vger.kernel.org" , "dmaengine@vger.kernel.org" , "vinod.koul@intel.com" , "vireshk@kernel.org" , "linux-snps-arc@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 10, 2016 at 6:28 PM, Eugeniy Paltsev wrote: > On Tue, 2016-11-08 at 15:36 +0200, Andy Shevchenko wrote: >> On Tue, 2016-11-08 at 12:22 +0000, Eugeniy Paltsev wrote: >> > On Mon, 2016-11-07 at 15:55 +0200, Andy Shevchenko wrote: >> > > > @@ -52,6 +55,7 @@ struct dw_dma_platform_data { >> > > > unsigned int nr_channels; >> > > > bool is_private; >> > > > bool is_memcpy; >> > > > >> > > > + bool only_quirks_used; >> > > Perhaps add if at the end of quirk list and name just >> > > > bool is_nollp; >> > > ...here >> > > >> > > bool use_quirks; >> What do think about shorten name? >> > I don't know better short and understandable name for "use_quirks" > variable. You can suggest your ideas if you want. This is my suggestion. In your patch I saw longer one. > >> > >> > I don't treat "is_nollp" as quirks like "is_private" or >> > "is_memcpy". >> > It is like general pdata field: we can easily read it from >> > autoconfig >> > registers (and we don't have any problem with that) in case of >> > pdata/device-tree absence (as opposed to quirks like "is_private" >> > or >> > "is_memcpy") >> > >> > So, in PATCH v3 series "is_nollp" used as regular pdata field. >> I still would consider is_nollp as a quirk since nothing prevents to >> override the hardware value (see Intel Quark case). >> > Do you mean this issue: > http://www.spinics.net/lists/linux-serial/msg22948.html > ? > > As I remember, we had problems with next code: > ---------------------------->8-------------------------- > channel_writel(dwc, LLP, DWC_LLP_LOC(0xffffffff)); > dwc->nollp = DWC_LLP_LOC(channel_readl(dwc, LLP)) == 0; > channel_writel(dwc, LLP, 0); > ---------------------------->8-------------------------- > which was executed if we didn't use autoconfig registers. > This code doesn't used anymore. > > And we don't have any problems with autoconfig registers! Yeah, but we have a quirk. > So in case of Intel Quark we will read "nollp" parameter from pdata or > from autoconfig registers (in case of pdata absence). It should work > fine in both cases. > Please correct me if I'm wrong. > > So, in my opinion, "is_nollp" should be used as regular pdata field. Let's discuss it a bit later. -- With Best Regards, Andy Shevchenko