From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751166AbdAMFcm (ORCPT ); Fri, 13 Jan 2017 00:32:42 -0500 Received: from mga01.intel.com ([192.55.52.88]:36757 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751109AbdAMFck (ORCPT ); Fri, 13 Jan 2017 00:32:40 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,220,1477983600"; d="scan'208";a="53336693" Date: Fri, 13 Jan 2017 10:59:39 +0530 From: Vinod Koul To: Appana Durga Kedareswara Rao Cc: "robh+dt@kernel.org" , "mark.rutland@arm.com" , "dan.j.williams@intel.com" , "michal.simek@xilinx.com" , Soren Brinkmann , "moritz.fischer@ettus.com" , "laurent.pinchart@ideasonboard.com" , "luis@debethencourt.com" , "Jose.Abreu@synopsys.com" , "dmaengine@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" Subject: Re: [PATCH v5 1/3] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor Message-ID: <20170113052939.GP3573@localhost> References: <1483771530-8545-1-git-send-email-appanad@xilinx.com> <1483771530-8545-2-git-send-email-appanad@xilinx.com> <20170110062349.GY3573@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 13, 2017 at 04:28:11AM +0000, Appana Durga Kedareswara Rao wrote: > Hi Vinod, > > Thanks for the review... > > > > On Sat, Jan 07, 2017 at 12:15:28PM +0530, Kedareswara rao Appana wrote: > > > Add channel idle state to ensure that dma descriptor is not > > > submitted when VDMA engine is in progress. > > > > any reason why you want to make your own varible and not use the HW to > > query > > as done earlier. It is not clear to me why that is removed from description > > We need to poll for a bit in the status register to know the dma state. > We are currently doing that in the driver hot path > To avoid this using own variables. It would be worthwhile to document these, down the line people may not remeber the motivation -- ~Vinod