From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E201B413 for ; Tue, 2 Aug 2016 06:57:08 +0000 (UTC) Received: from bear.ext.ti.com (bear.ext.ti.com [198.47.19.11]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 8E0AF198 for ; Tue, 2 Aug 2016 06:57:07 +0000 (UTC) To: Vinod Koul , Arnd Bergmann , Russell King - ARM Linux References: <3132432.DrxSMjl1Vi@wuerfel> <3411313.MV5bv347js@avalon> <23532527.pWCIkcecbr@wuerfel> <20160802044609.GS9681@localhost> From: Peter Ujfalusi Message-ID: <2ddeb98b-7bf8-aa21-2dee-9e02f9c59a92@ti.com> Date: Tue, 2 Aug 2016 09:48:53 +0300 MIME-Version: 1.0 In-Reply-To: <20160802044609.GS9681@localhost> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Cc: ksummit-discuss@lists.linuxfoundation.org, Dave Airlie , "Nikula, Jani" , Grant Likely , Linus Torvalds Subject: Re: [Ksummit-discuss] [CORE TOPIC] (group) maintainership models List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/02/16 07:46, Vinod Koul wrote: > On Mon, Aug 01, 2016 at 04:10:29PM +0200, Arnd Bergmann wrote: >> On Monday, August 1, 2016 10:36:01 AM CEST Laurent Pinchart wrote: >>> On Monday 01 Aug 2016 08:56:30 Arnd Bergmann wrote: >>>> On Sunday, July 31, 2016 11:27:53 PM CEST Vinod Koul wrote: >>>>> On Thu, Jul 28, 2016 at 10:44:23AM +0200, Arnd Bergmann wrote: >>>>>> config FOO >>>>>> >>>>>> bool "foo driver" if COMPILE_TEST && !ARCH_FOO >>>>>> default ARCH_FOO >>>>>> depends on GPIOLIB && I2C && OF && WHATEVER >>>>>> >>>>>> This becomes a silent always-on symbol if the platform is used, >>>>>> and user-selectable on every other platform with COMPILE_TEST. >>>>> >>>>> Yeah this seems a bit more better. I am perhaps thinking to add top >>>>> level arch dependency if required. I will try this out on DMAengine to >>>>> start with and ease my build tests >>>> >>>> Sounds good. Let me know if you end up having to add a 'depends on ARM' >>>> dependency anywhere, as that might indicate that we are doing something >>>> different on ARM that should be done in a more generic way. >>> >>> OMAP DMA comes to mind, we still depend on the implementation provided by >>> arch/arm/plat-omap/dma.c. >> >> That's a dependency on MACH_OMAP instead of ARM though, which is a bit >> different. >> >> (Getting offtopic and) speaking of this one, is anyone working >> on converting the last four or five drivers to the dmaengine framework? > > Rather lets' move this conversation to dmaengine list? > >> drivers/media/platform/omap/omap_vout_vrfb.c Needs the interleaved transfer type support in omap-dma. Now it is in -next. >> drivers/mtd/onenand/omap2.c Using memcpy, I have sent the patches: https://patchwork.kernel.org/patch/7842891/ https://patchwork.kernel.org/patch/7851881/ but I need to revisit. I think the 'fix' will be to drop the DMA support from it. >> drivers/usb/gadget/udc/omap_udc.c >> drivers/usb/musb/tusb6010_omap.c They are mostly slave implementations, but. As I recall they do some really interesting non symmetric setup for the TX/RX DMA which I still need to figure out. And I'm looking for HW to check for regression... >> (and a bit of drivers/video/fbdev/omap/omapfb_main.c) Hrm, that is OMAP1. Looks like highly coupled with mach-omap1/lcd_dma.c. This is going to be a bit complicated IMHO. > > Peter? > >> >> I guess we could improve build coverage by moving >> arch/arm/plat-omap/dma.c into drivers/dma/omap-dma.c, but that >> has the disadvantage of exposing a nonstandard interface from >> somewhere inside of the dmaengine subsystem. > > yeah that won't be nice. I think we should get these removed... We have omap > as well as edma driver in dmaengine. I'm not going to move the legacy API under dmaengine, it makes no sense. My plan is to do what I did with the eDMA driver stack: - convert drivers using the legacy API to dmaengine - 'merge' the code from plat-omap to the dmaengine driver - while doing this the legacy API will vanish along with the plat-omap/dma.c As with the eDMA, the sDMA stack will need some cleanup, but the good thing is that the dmaengine driver have minimal dependency on the legacy plat-omap/dma.c API. -- Péter