From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sinan Kaya Subject: Re: [PATCH V7 3/3] dma: add Qualcomm Technologies HIDMA channel driver Date: Tue, 8 Dec 2015 09:33:45 -0500 Message-ID: <5666EA49.2030206@codeaurora.org> References: <1448245707-27499-1-git-send-email-okaya@codeaurora.org> <1448245707-27499-4-git-send-email-okaya@codeaurora.org> <20151130085948.GC3901@localhost> <565CAC4C.7080909@codeaurora.org> <20151201113458.GL3901@localhost> <565E0E1D.1040505@codeaurora.org> <565F40A5.2040701@codeaurora.org> <20151205080030.GJ1854@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20151205080030.GJ1854@localhost> Sender: linux-kernel-owner@vger.kernel.org To: Vinod Koul Cc: dmaengine@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, agross@codeaurora.org, arnd@arndb.de, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On 12/5/2015 3:00 AM, Vinod Koul wrote: > On Wed, Dec 02, 2015 at 02:04:05PM -0500, Sinan Kaya wrote: >>>>> You are missing the point. Channel can be paused, yes but the descriptor >>>>> is in queue and is not paused. The descriptor running is paused, yes. >>>>> There is subtle difference between these >>> I'll follow your recommendation. PAUSE for the currently active >>> descriptor and DMA_IN_PROGRESS for the rest. >>> >> >> I'm now confused. >> >> I looked at several DMA driver implementations. >> >> 1. They call dma_cookie_status function to see if the job is done. >> 2. If done, they return right ahead. >> 3. Otherwise, dma_cookie_status returns DMA_IN_PROGRESS. >> 4. Next the code checks if the channel is paused and return value is >> DMA_IN_PROGRESS. The code changes return code to DMA_PAUSED. >> >> Whereas, I was returning paused first before even checking if the >> descriptor is done. Are you OK with the sequence 1..4 above? > > Yes am okay with this with slight change in 4. > > You should set to PAUSED only for current descriptor and not for the ones in > queue > OK, I'll work on it. -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project