From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: + pm-gxfb-add-hook-to-pm-console-layer-that-allows-disabling-of-suspen d-vt-switch.patch added to -mm tree Date: Thu, 13 Mar 2008 08:43:32 +0100 Message-ID: <20080313074332.GA19117@elf.ucw.cz> References: <200803120527.m2C5RmWl011967@imap1.linux-foundation.org> <20080312085149.GA3993@ucw.cz> <20080312144506.GE1018@cosmic.amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20080312144506.GE1018@cosmic.amd.com> Sender: linux-kernel-owner@vger.kernel.org To: Jordan Crouse Cc: akpm@linux-foundation.org, kernel list , Linux-pm mailing list , mm-commits@vger.kernel.org, dilinger@queued.net, adaplas@pol.net, dilinger@debian.org, rjw@sisk.pl List-Id: linux-pm@vger.kernel.org > > > (Note: I'm not convinced that console_sem is the best way to protect this, but > > > we should probably have some form of locking..) > > > > I guess this is okay for now, but we probably want to make it more > > elaborate in future. > > > > Console switch is there to make sure kernel (not X) owns the graphical > > hardware. > > > > That is unneccessary for gxfb since X never owns graphics hardware, > > good. (I do not see why it is optional, then. Do you really want to > > see tty1?) > > Its the dream for the lxfb and gxfb to own the graphics hardware > completely (at least, thats what Jim Gettys keeps pounding in to my > brain), but we're not quite there yet. What we have here are > framebuffer drivers that are intelligent enough to save and restore the > state of the graphics engine, which is still a lot better then most other > drivers. Ok. > > Now, question is what happens with two graphics cards, one of them > > driven by X. Fortunately that is uncommon. > > We would be screwed. But since the Geode has built in graphics logic, > it doesn't make much sense to use an external card, so we'll mostly > avoid this problem. But even if it happens, we'll have the VT switch > available in a pinch. > > > Also, it would be nice to make the logic the other way around. Move vt > > switching to the drivers that need it because X can be expected to own > > the hardware. > > Conservation of energy. Its easier to make 3 or 4 drivers opt out of Nice euphemism. You did quick hack instead of proper solution, and someone will have to clean it up sooner or later... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html