From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by nz-out-0506.google.com with SMTP id f1so2557043nzc for ; Wed, 21 Feb 2007 15:40:52 -0800 (PST) Subject: Re: [Linux-fbdev-devel] [PATCH 2.6.20 1/1] fbdev, mm: hecuba/E-Ink fbdev driver From: "Antonino A. Daplas" In-Reply-To: <45a44e480702192013s7d49d05ai31e576f0448a485e@mail.gmail.com> References: <20070217104215.GB25512@localhost> <1171715652.5186.7.camel@lappy> <45a44e480702170525n9a15fafpb370cb93f1c1fcba@mail.gmail.com> <20070217135922.GA15373@linux-sh.org> <45a44e480702180331t7e76c396j1a9861f689d4186b@mail.gmail.com> <20070218235741.GA22298@linux-sh.org> <45a44e480702192013s7d49d05ai31e576f0448a485e@mail.gmail.com> Content-Type: text/plain Date: Thu, 22 Feb 2007 07:43:33 +0800 Message-Id: <1172101413.4217.18.camel@daplas> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: linux-fbdev-devel@lists.sourceforge.net Cc: Paul Mundt , Jaya Kumar , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Geert.Uytterhoeven@sonycom.com, jsimmons@infradead.org List-ID: On Mon, 2007-02-19 at 23:13 -0500, Jaya Kumar wrote: > On 2/18/07, Paul Mundt wrote: > > Given that, this would have to be something that's dealt with at the > > subsystem level rather than in individual drivers, hence the desire to > > see something like this more generically visible. > > > > Hi Peter, Paul, fbdev folk, > > Ok. Here's what I'm thinking for abstracting this: > > fbdev drivers would setup fb_mmap with their own_mmap as usual. In > own_mmap, they would do what they normally do and setup a vm_ops. They > are free to have their own nopage handler but would set the > page_mkwrite handler to be fbdev_deferred_io_mkwrite(). > fbdev_deferred_io_mkwrite would build up the list of touched pages and > pass it to a delayed workqueue which would then mkclean on each page Yes, this functionality is sorely needed by more than a few driver writers. > and then pass a copy of that page list down to a driver's callback > function. The fbdev driver's callback function can then do the actual > IO to the framebuffer or coalesce DMA based on the provided page list. > I would like to add something like the following to struct fb_info: > > #ifdef CONFIG_FB_DEFERRED_IO > struct fb_deferred_io *defio; > #endif > > to store the mutex (to protect the page list), the touched page list, > and the driver's callback function. > > I hope this sounds sufficiently generic to meet everyone's (the two of > us? :) needs. There's definitely more than two :-). For the past several years, various people have been asking for this functionality. So yes, implementing this in a generic manner will be a big help. Tony -- 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