From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCH v5 1/3] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor Date: Fri, 13 Jan 2017 10:59:39 +0530 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-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Appana Durga Kedareswara Rao Cc: "mark.rutland@arm.com" , "moritz.fischer@ettus.com" , "devicetree@vger.kernel.org" , "michal.simek@xilinx.com" , "linux-kernel@vger.kernel.org" , "robh+dt@kernel.org" , Soren Brinkmann , "luis@debethencourt.com" , "dmaengine@vger.kernel.org" , "dan.j.williams@intel.com" , "Jose.Abreu@synopsys.com" , "linux-arm-kernel@lists.infradead.org" , "laurent.pinchart@ideasonboard.com" List-Id: devicetree@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