From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162455AbdD0NeL (ORCPT ); Thu, 27 Apr 2017 09:34:11 -0400 Received: from mga09.intel.com ([134.134.136.24]:40963 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033579AbdD0NeC (ORCPT ); Thu, 27 Apr 2017 09:34:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,384,1488873600"; d="scan'208";a="1124067601" Message-ID: <1493300030.24567.235.camel@linux.intel.com> Subject: Re: [PATCH v2 2/2] dmaengine: Add DW AXI DMAC driver From: Andy Shevchenko To: Eugeniy Paltsev , Lars-Peter Clausen Cc: "vinod.koul@intel.com" , "linux-kernel@vger.kernel.org" , "robh+dt@kernel.org" , "Alexey.Brodkin@synopsys.com" , "devicetree@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" , "dan.j.williams@intel.com" , "dmaengine@vger.kernel.org" Date: Thu, 27 Apr 2017 16:33:50 +0300 In-Reply-To: <1493299300.25985.17.camel@synopsys.com> References: <1491573855-1039-1-git-send-email-Eugeniy.Paltsev@synopsys.com> <1491573855-1039-3-git-send-email-Eugeniy.Paltsev@synopsys.com> <1492518695.24567.56.camel@linux.intel.com> <1492784977.16657.6.camel@synopsys.com> <1492787583.24567.120.camel@linux.intel.com> <1493049305.25985.4.camel@synopsys.com> <1493052970.24567.168.camel@linux.intel.com> <1493133369.25985.10.camel@synopsys.com> <1493143941.24567.196.camel@linux.intel.com> <1493219075.24567.211.camel@linux.intel.com> <1493299300.25985.17.camel@synopsys.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2017-04-27 at 13:21 +0000, Eugeniy Paltsev wrote: > On Wed, 2017-04-26 at 18:04 +0300, Andy Shevchenko wrote: > > On Tue, 2017-04-25 at 21:12 +0300, Andy Shevchenko wrote: > > > On Tue, 2017-04-25 at 15:16 +0000, Eugeniy Paltsev wrote: > > > > On Mon, 2017-04-24 at 19:56 +0300, Andy Shevchenko wrote: > > > > > On Mon, 2017-04-24 at 15:55 +0000, Eugeniy Paltsev wrote: > > > > Hmm, this looks OK. (In my example (hsu/hsu.c driver) error > > > > descriptors > > > > are not freed even after terminate_all is called) > > > > > > If it's active it will be freed. > > > Otherwise caller should check somewhere that descriptor fails. > > > > > > But actually this is fragile and we need to monitor failed > > > descriptors. > > > Thanks for reporting. > > > > > > > > > > > > Of course, if you want to keep by some reason (should be > > > > > stated > > > > > what > > > > > the reason in comment) erred descriptors, you can do that. > > > > > > > > So, I'll create desc_error list and store failed descriptors in > > > > this > > > > list until terminate_all() is called. > > > > Is it OK implementation? > > > > > > Nope, we need to amend virt-chan API for that. I'm on it. Will > > > send > > > a series soon. > > > > I have to correct what I wrote before. > > > > We have two options: > > a) one I proposed above; > > b) move descriptor to complete list and call complete callback with > > result. > > > > So, it looks like the b) variant is what is done already in 4 (did I > > calculate correctly?) drivers and respective users. > > In my opinion we should call error descriptor complete callback. > But I don't think we should move error descriptor to desc_completed > list. > > When descriptor following our error descriptor will be completed > successfully vchan tasklet will be called. > So all descriptors from desc_completed list will be freed (including > our error descriptor) > We'll lost information about error descriptors and we'll not be able > to > return correct status from dma_async_is_tx_complete(). While I more agree on the point that we better to have explicit list of failed descriptors, here is another point that user (which is interested in error checking) has to provide callback_result instead of callback. > In my opinion, we should create desc_error list. > When we get error we'll move descriptor to desc_error list and call > complete callback. Vinod, Lars, others, what is(are) your opinion(s)? -- Andy Shevchenko Intel Finland Oy From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v2 2/2] dmaengine: Add DW AXI DMAC driver Date: Thu, 27 Apr 2017 16:33:50 +0300 Message-ID: <1493300030.24567.235.camel@linux.intel.com> References: <1491573855-1039-1-git-send-email-Eugeniy.Paltsev@synopsys.com> <1491573855-1039-3-git-send-email-Eugeniy.Paltsev@synopsys.com> <1492518695.24567.56.camel@linux.intel.com> <1492784977.16657.6.camel@synopsys.com> <1492787583.24567.120.camel@linux.intel.com> <1493049305.25985.4.camel@synopsys.com> <1493052970.24567.168.camel@linux.intel.com> <1493133369.25985.10.camel@synopsys.com> <1493143941.24567.196.camel@linux.intel.com> <1493219075.24567.211.camel@linux.intel.com> <1493299300.25985.17.camel@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1493299300.25985.17.camel-HKixBCOQz3hWk0Htik3J/w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eugeniy Paltsev , Lars-Peter Clausen Cc: "vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "Alexey.Brodkin-HKixBCOQz3hWk0Htik3J/w@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-snps-arc-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org On Thu, 2017-04-27 at 13:21 +0000, Eugeniy Paltsev wrote: > On Wed, 2017-04-26 at 18:04 +0300, Andy Shevchenko wrote: > > On Tue, 2017-04-25 at 21:12 +0300, Andy Shevchenko wrote: > > > On Tue, 2017-04-25 at 15:16 +0000, Eugeniy Paltsev wrote: > > > > On Mon, 2017-04-24 at 19:56 +0300, Andy Shevchenko wrote: > > > > > On Mon, 2017-04-24 at 15:55 +0000, Eugeniy Paltsev wrote: > > > > Hmm, this looks OK. (In my example (hsu/hsu.c driver) error > > > > descriptors > > > > are not freed even after terminate_all is called) > > > > > > If it's active it will be freed. > > > Otherwise caller should check somewhere that descriptor fails. > > > > > > But actually this is fragile and we need to monitor failed > > > descriptors. > > > Thanks for reporting. > > > > > > > > > > > > Of course, if you want to keep by some reason (should be > > > > > stated > > > > > what > > > > > the reason in comment) erred descriptors, you can do that. > > > > > > > > So, I'll create desc_error list and store failed descriptors in > > > > this > > > > list until terminate_all() is called. > > > > Is it OK implementation? > > > > > > Nope, we need to amend virt-chan API for that. I'm on it. Will > > > send > > > a series soon. > > > > I have to correct what I wrote before. > > > > We have two options: > > a) one I proposed above; > > b) move descriptor to complete list and call complete callback with > > result. > > > > So, it looks like the b) variant is what is done already in 4 (did I > > calculate correctly?) drivers and respective users. > > In my opinion we should call error descriptor complete callback. > But I don't think we should move error descriptor to desc_completed > list. > > When descriptor following our error descriptor will be completed > successfully vchan tasklet will be called. > So all descriptors from desc_completed list will be freed (including > our error descriptor) > We'll lost information about error descriptors and we'll not be able > to > return correct status from dma_async_is_tx_complete(). While I more agree on the point that we better to have explicit list of failed descriptors, here is another point that user (which is interested in error checking) has to provide callback_result instead of callback. > In my opinion, we should create desc_error list. > When we get error we'll move descriptor to desc_error list and call > complete callback. Vinod, Lars, others, what is(are) your opinion(s)? -- Andy Shevchenko Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: andriy.shevchenko@linux.intel.com (Andy Shevchenko) Date: Thu, 27 Apr 2017 16:33:50 +0300 Subject: [PATCH v2 2/2] dmaengine: Add DW AXI DMAC driver In-Reply-To: <1493299300.25985.17.camel@synopsys.com> References: <1491573855-1039-1-git-send-email-Eugeniy.Paltsev@synopsys.com> <1491573855-1039-3-git-send-email-Eugeniy.Paltsev@synopsys.com> <1492518695.24567.56.camel@linux.intel.com> <1492784977.16657.6.camel@synopsys.com> <1492787583.24567.120.camel@linux.intel.com> <1493049305.25985.4.camel@synopsys.com> <1493052970.24567.168.camel@linux.intel.com> <1493133369.25985.10.camel@synopsys.com> <1493143941.24567.196.camel@linux.intel.com> <1493219075.24567.211.camel@linux.intel.com> <1493299300.25985.17.camel@synopsys.com> List-ID: Message-ID: <1493300030.24567.235.camel@linux.intel.com> To: linux-snps-arc@lists.infradead.org On Thu, 2017-04-27@13:21 +0000, Eugeniy Paltsev wrote: > On Wed, 2017-04-26@18:04 +0300, Andy Shevchenko wrote: > > On Tue, 2017-04-25@21:12 +0300, Andy Shevchenko wrote: > > > On Tue, 2017-04-25@15:16 +0000, Eugeniy Paltsev wrote: > > > > On Mon, 2017-04-24@19:56 +0300, Andy Shevchenko wrote: > > > > > On Mon, 2017-04-24@15:55 +0000, Eugeniy Paltsev wrote: > > > > Hmm, this looks OK. (In my example (hsu/hsu.c driver) error > > > > descriptors > > > > are not freed even after terminate_all is called) > > > > > > If it's active it will be freed. > > > Otherwise caller should check somewhere that descriptor fails. > > > > > > But actually this is fragile and we need to monitor failed > > > descriptors. > > > Thanks for reporting. > > > > > > > > > > > > Of course, if you want to keep by some reason (should be > > > > > stated > > > > > what > > > > > the reason in comment) erred descriptors, you can do that. > > > > > > > > So, I'll create desc_error list and store failed descriptors in > > > > this > > > > list until terminate_all() is called. > > > > Is it OK implementation? > > > > > > Nope, we need to amend virt-chan API for that. I'm on it. Will > > > send > > > a series soon. > > > > I have to correct what I wrote before. > > > > We have two options: > > a) one I proposed above; > > b) move descriptor to complete list and call complete callback with > > result. > > > > So, it looks like the b) variant is what is done already in 4 (did I > > calculate correctly?) drivers and respective users. > > In my opinion we should call error descriptor complete callback. > But I don't think we should move error descriptor to desc_completed > list. > > When descriptor following our error descriptor will be completed > successfully vchan tasklet will be called. > So all descriptors from desc_completed list will be freed (including > our error descriptor) > We'll lost information about error descriptors and we'll not be able > to > return correct status from dma_async_is_tx_complete(). While I more agree on the point that we better to have explicit list of failed descriptors, here is another point that user (which is interested in error checking) has to provide callback_result instead of callback. > In my opinion, we should create desc_error list. > When we get error we'll move descriptor to desc_error list and call > complete callback. Vinod, Lars, others, what is(are) your opinion(s)? -- Andy Shevchenko Intel Finland Oy