Date: Sat, 24 Jan 1998 03:10:00 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: David Dawes <dawes@rf900.physics.usyd.edu.au> Cc: Stefan Esser <se@FreeBSD.ORG>, hackers@FreeBSD.ORG, rgooch@atnf.csiro.au Subject: Re: ANNOUNCE: Fastvid module available! Message-ID: <199801241110.DAA21360@rah.star-gate.com> In-Reply-To: Your message of "Sat, 24 Jan 1998 13:50:49 %2B1100." <19980124135049.46451@rf900.physics.usyd.edu.au>
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There are other issues which just simply lead me to believe that the best possible way to implement fastvid is to provide a system call and as for co-operating with linux developers thats fine with me . So Richard, can you bring us up to speed on what you are up to? Tnks, Amancio > On Thu, Jan 22, 1998 at 09:17:31PM +0100, Stefan Esser wrote: > > >> 4. If the pci code is up to it it would be nice to dump the pci configuration > >> for all the devices and if possible properly identify the devices. > >> The probe code already does some of this so it should not be that > >> difficult if the pci code can return a list of currently installed pci > >> devices along with their respective configuration. > > > >The PCI code already is "up to it". You only have to call a > >"fastvid" function from the VGA attach code. All the PCI map > >registers are available, and you can just make the largest > >memory mapped region "fast". > > > >Multiple regions should be OK, too, if supported by the CPU. > > Only do this for the framebuffer areas, not memory mapped I/O areas. > Those chipsets that have separate memory regions allocated for the > framebuffer and MMIO typically mark the framebuffer area a pre-fetchable, > and the MMIO area as non-pre-fetchable. Some cards (some examples are > some S3 cards and some Mach64-based cards) have a single region, which > is divided up into framebuffer and MMIO. It would be marked as > non-pre-fetchable. To use something like fastvid effectively in that > case, you need to have some knowledge of how that area is organised. > Furthermore, some S3 chipsets have a bug that can result in the PCI > BIOS giving them a memory area aligned to 32MB instead of the required > 64MB. This can also result in a clash between the video card memory > and that of other PCI devices. The XFree86 S3 server detects this and > remaps. If the kernel is going to do fastvid, it should know about this > too. > > While I generally like the idea of the OS taking care of this sort of > thing, it can still be useful to provide a way for something like the > Xserver to check and maybe change such things. > > I don't know if any of you have had a look at what the Linux people > are doing in this area. If you're interested, you can contact > Richard Gooch <rgooch@atnf.csiro.au>. > > David
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