On Tue, Jul 3, 2012 at 2:57 PM, Alex Deucher <[email protected]> wrote: > On Tue, Jul 3, 2012 at 7:57 AM, Dave Airlie <[email protected]> wrote: >> (forgot list first time I sent this). >> >> On Mon, Jul 2, 2012 at 10:03 PM, Keith Packard <[email protected]> wrote: >>> Dave Airlie <[email protected]> writes: >>> >>>> On Mon, Jul 2, 2012 at 8:54 PM, Keith Packard <[email protected]> wrote: >>>>> Dave Airlie <[email protected]> writes: >>>>> >>>>> >>>>>> Yes thats going to be the standard on switchable GPU machines, two >>>>>> masters >>>>>> and the ability to jump between them. In that case max master is one, >>>>>> and you'd >>>>>> have to set the provider roles. If maxmaster > 1 then xinerama >>>>>> emulation is available. >>>>> >>>>> In those machines, isn't the limitation that only one of them can drive >>>>> the LVDS panel at a time? Can't you have the internal GPU driving the >>>>> LVDS while the external GPU drives other outputs? >>>> >>>> Yes but you don't configure it in xinerama mode for that, there are >>>> mux and muxless configurations. >>> >>> I think I understand what the hardware does now, just trying to figure >>> out how to provide a reasonable description of that to applications >>> while not just providing a big 'muxless/muxed' switch, which seems >>> restricted to precisely how the hardware that we have works today. >>> >>>> In mux configuration, you switch the mux between GPUs when the master >>>> is switched. >>> >>> Right, the mux just rewires things so that the other GPU is hooked up to >>> the LVDS. I'd expect the LVDS outputs to reflect a suitable connection >>> status for these changes. >>> >>> The only question is how you drive the mux switch. Is this switch >>> selectable per-output? Or is is global? And, how do we label which >>> outputs are affected by a global switch? >> >> We don't really know with 100% certainty since the specs for all these >> things are closed. We've done a lot of RE work, and it mostly appears >> to be a single global switch that turns any connected outputs. There is >> a table in the intel bios which can tell you about which outputs are muxed >> etc, but this isn't always present. Again we also have laptops that have >> a mux but don't expose this table, as they only have the MUX so the >> BIOS can pick IGP/discrete for Vista, and Windows 7 operates in >> muxless mode. >> >> The current problem is I'm not sure any OS exposes muxless and mux >> in one OS. Mac OSX always uses muxed, Vista the same, and I think >> Windows 7 always exposes muxless if the bios reports optimus support >> or the AMD equivalent. > > All new AMD systems are muxless and I suspect most other vendors are > doing the same. I'm wondering if there is any reason to bother with > proper muxed support at all? We should be able to treat muxed systems > as muxless just fine. >
Apple hw is the only one I know off persisting with a muxed design, Whether it buys us much supporting the mux on it I'm not sure, I've no idea to what degree they power down the intel hardware on it. Dave. _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
