From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Koul, Vinod" Subject: Re: [PATCH V2 6/6] spi/spi-pl022: Request/free DMA channels as and when required. Date: Fri, 19 Aug 2011 19:19:04 +0530 Message-ID: <1313761744.18591.5.camel@vkoul-udesk3> References: <566c0525199f498f04422d4c3b2ddd7466648c20.1312965742.git.viresh.kumar@st.com> <20110810090042.GE1831@n2100.arm.linux.org.uk> <4E424F7B.2000800@st.com> <438BB0150E931F4B9CE701519A4463010871804A15@bgsmsx502.gar.corp.intel.com> <20110810104025.GK1831@n2100.arm.linux.org.uk> <1313009883.1603.25.camel@vkoul-udesk3> <1313495727.1603.83.camel@vkoul-udesk3> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "pratyush.anand@st.com" , "rajeev-dlh.kumar@st.com" , Russell King - ARM Linux , "bhupesh.sharma@st.com" , "armando.visconti@st.com" , Linus Walleij , "grant.likely@secretlab.ca" , "spi-devel-general@lists.sourceforge.net" , "vipin.kumar@st.com" , "shiraz.hashim@st.com" , "Amit.VIRDI@st.com" , "vipulkumar.samar@st.com" , "viresh.linux@gmail.com" , "deepak.sikri@st.com" , "bhavna.yadav@st.com" , "Williams, Dan J" , "linux-arm-kernel@lists.infradead.org" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org On Tue, 2011-08-16 at 20:21 +0530, Jassi Brar wrote: > On Tue, Aug 16, 2011 at 5:25 PM, Koul, Vinod wrote: > > > Sorry I still don't get this schema and how it can be scaled and be > > generic enough to let it carry with various implementations. > > > > Can you publish your complete idea rather than bits and pieces... > I already explained the complete idea. I don't have any implementation yet. > Clients and dmaengine.c is easier to manage. > But changes to >20 dmac drivers is the biggest effort - though they anyway > need such modifications if we are to have the DMAENGINE utopia someday. > In free time, I will modify a dmac driver or two, but it might take > prohibitively > long if I am expected to update possibly all the 20 dmac drivers and the backend > platforms by It would help if you can send RFC of changes in one driver and dmaengine changes. I want to get the dmaengine changes understood well and be able to deal with all scenarios we have. Without complete code its rather hard :( We can do these changes to other drivers over a period of time, that can be taken over a period of time and we can manage that, this part is easy. > a) Making dmac drivers platform agnostic and for re-routable ReqSig-Peri map. > That implies dmac drivers managing 'virtual-channel' front end > and physical > channel and ReqSig->Peri link management in the backend with > help from platform. > b) Modifying platforms/boards to pass channel map and link re-routing callback > pointers to generic dmac drivers. -- ~Vinod