From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 11 Oct 1999 19:14:40 -0400 (EDT) From: James Simmons Subject: Re: MMIO regions In-Reply-To: <38021DE1.816F44A2@pobox.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Jeff Garzik Cc: "Stephen C. Tweedie" , Linux MM List-ID: On Mon, 11 Oct 1999, Jeff Garzik wrote: > > It is an unfortunate, but true, fact that the broken video hardware > > doesn't let you provide memory mapped access which is (a) fast, (b) > > totally safe, and (c) functional. Choose which of a, b and c you are > > willing to sacrifice and then we can look for solutions. DRI sacrifices > > (b), for example, by making the locking cooperative rather than > > compulsory. The basic unaccelerated fbcon sacrifices (c). Using VM > > protection would sacrifice (a). It's not the ideal choice, sadly. > > Seems like it would make sense for an fbcon driver to specify the level > of safety (and thus the level of speed penalty). Well the new system I have implemented has elminated porting MMIO regions to userspace. This makes way for DRI or any other solutions that might come down the road. Also I have written fbcon to release the console system on explict opening of fbdev. This way no accels are running in the kernel while something like X is running. Especially if something like DRI is running. This prevents any possible conflicts. Yes I sacrificed some functionality of the current fbcon for DRI. I hope DRI will in turn help support fbcon and help us write drivers. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/