From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id 9B1B36B025E for ; Tue, 3 Oct 2017 11:06:33 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id r18so5879910qkh.4 for ; Tue, 03 Oct 2017 08:06:33 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id i31sor5880815qtc.78.2017.10.03.08.06.32 for (Google Transport Security); Tue, 03 Oct 2017 08:06:32 -0700 (PDT) Date: Tue, 3 Oct 2017 11:06:30 -0400 (EDT) From: Nicolas Pitre Subject: Re: [PATCH v4 1/5] cramfs: direct memory access support In-Reply-To: <20171003145921.GA9954@infradead.org> Message-ID: References: <20170927233224.31676-1-nicolas.pitre@linaro.org> <20170927233224.31676-2-nicolas.pitre@linaro.org> <20171001082955.GA17116@infradead.org> <20171003145921.GA9954@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Alexander Viro , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-embedded@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Brandt , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org On Tue, 3 Oct 2017, Christoph Hellwig wrote: > On Sun, Oct 01, 2017 at 06:27:11PM -0400, Nicolas Pitre wrote: > > If you prefer, the physical address could be specified with a Kconfig > > symbol just like the kernel link address. Personally I think it is best > > to keep it along with the other root mount args. But going all the way > > with a dynamic driver binding interface and a dummy intermediate name is > > like using a sledge hammer to kill an ant: it will work of course, but > > given the context it is prone to errors due to the added manipulations > > mentioned previously ... and a tad overkill. > > As soon as a kernel enables CRAMFS_PHYSMEM this mount option is > available, so you don't just need to think of your use case. What other use cases do you have in mind? > The normal way for doings this would be to specify it in the device > tree. And specify it how? Creating a pseudo device and passing that instead of the actual physical address? What is the advantage? And what about targets that don't use DT? Yes, there are still quite a few out there. Nicolas -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org