From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH v2 03/16] ARM: dts: provide DMA config to pxamci Date: Mon, 16 Dec 2013 12:58:44 +0100 Message-ID: <52AEEAF4.3010703@metafoo.de> References: <1386543229-1542-1-git-send-email-ynvich@gmail.com> <1386901645-28895-1-git-send-email-ynvich@gmail.com> <1386901645-28895-4-git-send-email-ynvich@gmail.com> <201312142006.26979.arnd@arndb.de> <1387049660.7152.317.camel@host5.omatika.ru> <52AECEB2.4070807@gmail.com> <1387194450.13062.134.camel@host5.omatika.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1387194450.13062.134.camel-7ZSkjCHmnyFmet/iJI8ZvA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sergei Ianovich Cc: Daniel Mack , Arnd Bergmann , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Rob Landley , Russell King , Chris Ball , Viresh Kumar , Shawn Guo , Haojian Zhuang , "open list:OPEN FIRMWARE AND..." , DOCUMENTATION , linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 12/16/2013 12:47 PM, Sergei Ianovich wrote: > On Mon, 2013-12-16 at 10:58 +0100, Daniel Mack wrote: >> On 12/14/2013 08:34 PM, Sergei Ianovich wrote: >>> On Sat, 2013-12-14 at 20:06 +0100, Arnd Bergmann wrote: >> >>>> The patch looks ok in case we are merging your patches for 3.14 >>>> and Daniel's patches later than that. If they end up in the >>>> same merge window however, we'd have to be care to resolve >>>> the obvious conflict in a proper way. >>> >>> The most recently published Daniel's patch (Aug 2013) wraps >>> IORESOURCE_DMA handling on DT presence in a similar way, >> >> Erm, no it doesn't. My patch uses dma_request_slave_channel_compat() in >> DT case, and that works fine with the current version of pdma, and >> there's no need to read the "dmas" properties directly. >> >> If you want to provide a way to simply denote the dma channel numbers, >> without looking at the actual phandle, then yes, we could merge this >> patch first, but it would be effectively reverted a proper implementation. > > Daniel is right. His patch doesn't need to read "dmas" directly. So my > patch won't need to change drivers/mmc/host/pxamci.c at all, if it is > applied after Daniel's one. > Btw. any driver that parses the dmas property manually should be considered broken. This is a classical layering violation. The layout of the dma specifier is DMA controller specific and should be completely transparent to the device driver. - Lars -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html