sony-vaio-z-series team mailing list archive

[Adam Hill <sidepipeuk@xxxxxxxxx>]

> When booting with an old kernel (for Nvidia) or Kubuntu (for Intel), does
> it matter what position the physical switch is in?  Do the OS's actually
> read the switch value or do these each find their respective card and
> initialize it regardless of the switch?

	With the old kernel trick, yes it does - the BIOS selects the correct 
graphics card on next boot, with the other being completely invisible. Without 
this trick, regardless of the switch position *I think* that the machine 
initialises the Intel card at boot time, though both cards are enabled and 
powered up it seems. When using a kernel with the sony-laptop z series module 
from Norbert ( patched with my VPC mod ) it is possible to power down the 
NVidia card BUT it still appears on the bus, which causes at least some of the 
issues. My hacked module reads the switch position at boot time and disables 
the NVidia card if in stamina mode, or auto mode with no mains, but after that 
the switch just generates an event and you would need software to read it and 
take appropriate action. Probably pointless at this stage because even if we 
could get both cards working without rebooting, "appropriate action" involves 
restarting X.

	I guess that in future it would be nice to get the X developers to add 
the possibility of restarting the server and restoring all of the windows etc 
without killing the processes controlling them - but we are waaay off that 
yet.
 
> Related question: does the BIOS even care about the switch position or is
> that only an OS thing?

	As above - depends on whether you boot the old kernel first. Once booted 
though, no.

> What layer does the RAID0 reside at?  If it's a hardware/BIOS thing,
> shouldn't it be invisible to the bootloader?

	Its software RAID but with BIOS support. As far as the OS is concerned it 
is software, I think that all the BIOS support adds is the ability to boot 
from it, but I'm no expert. The net effect is that as far as Linux is 
concerned, its software, and needs the same dmraid type setup that you would 
use for a pure software RAID implementation.
 
> The solution is here?  http://www.voip-x.co.uk/files/adam/
> 
> In the readme you mention that the intel solution is complicated but it
> does seem the most promising, yes?  At least, it doesn't require that
> silly old-kernel-reboot trick like the nvidia does.  If I follow your
> instructions to use intel, does this mean the nvidia card is powered off?

	If you have a 1920x1080 panel and an i7 processor, then you can use the 
kernel and rc script in there to get a system that works with the Intel card 
without any boot tricks etc. The NVidia card is ( well, seems to be ) powered 
off and so battery drain is acceptable. I think that it should work with the 
i5 processor and that panel too.

	If you have any other panel then at present there isn't an Intel driver 
that will support it that I know of, you'd be stuck with Vesa ( 1024x768 max. 
) I am trying to find a solution to this but don't have much time and ( more 
crucially ) don't have a VPC machine with a 1600x900 screen to test on or any 
detailed knowledge of the Arrandale graphics core, so progress is painful :(. 
There may be something very simple that is causing it not to work at lower 
resolutions but without a test machine it's like looking for a needle in a 
haystack when you are telling someone else where to look!

Adam.