Adam Jackson wrote: > On Fri, 2009-11-20 at 13:23 -0800, Mike Travis wrote: >> Hi Adam, Jesse, >> >> We here at SGI are getting ready to deploy the SGI Ultraviolet >> system (see refs below) and the question came up about supporting >> legacy I/O for multiple VGA cards. The UV architecture requires >> some additional setup when changing the "owner" of the legacy >> VGA I/O space. >> >> I've been trying to follow the progress of the VGA Arbiter, and >> it's use by X, as a means of providing the kernel hook to execute >> this setup. Can you (or someone) enlighten me as to whether >> a.) X still requires the use of legacy I/O [or are all accesses >> being done with MMIO operations]? and b.) is the plan still to use >> the VGA Arbiter as currently implemented in linux-2.6.32? > > It depends on the driver, really. X doesn't try to poke the VGA space > on its own anymore (pretty sure I got rid of all that), but if your > driver uses the vgahw module or does I/O directly, then that needs > wrapping. > > My understanding is, by default the VGA arbiter support code in X will > assume the driver _does_ need VGA arbitration, unless the driver opts > out of it, and will wrap device access for you. So whatever extra setup > your platform needs should Just Work if you hook it up to the > arbitration grant in the kernel. > > - ajax
Thanks Adam! That is good news indeed. >From my understanding, the device driver is also "legacy I/O" free, or striving to be. Cheers. _______________________________________________ xorg-devel mailing list [email protected] http://lists.x.org/mailman/listinfo/xorg-devel
