On Mon, 2007-02-19 at 23:13 -0500, Jaya Kumar wrote: > On 2/18/07, Paul Mundt <[EMAIL PROTECTED]> 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
