tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: xorg pci probing

Hash: SHA1


On Jan 18, 2011, at 6:19 AM, Christoph Egger wrote:

On Tue, Jan 18, 2011 at 11:39:35AM +0100, Christoph Egger wrote:
The function pci_device_is_boot_vga() is supposed to return
'true' for the pci vga device the firmware uses which is not
neccessarily the OS console device (it can be a serial console).

Ok. But your function answers "this is the vga device where wsdisplay0 attached" instead - is that a safe bet, especially in case you boot with
a serial console?

According to macallan@  ttyE* is the first graphic device,
ttyF* the second, ttyG* the third, etc.

So yes, it is safe.

I wouldn't call it 'safe' but 'safe enough'. Most ports will try to make sure wsdisplay0 is the firmware console but if the console is a serial line there may or may not be a wsdisplay0. On the other hand, what X tries to do here, as far as I can tell, is to make sure :0 is where the user expects it which would still be wsdisplay0 even in the serial console case.

I still completely fail to see why X would like to know this detail and
what a wrong answer would mean. If it's just a wrong default display
but fixable via config file, it's fine.

The pci probing happens before the config file comes into play.
That's why the config file has no effect.

I would call that a bug in X though - it should be able to use arbitrary PCI devices if there's a driver that can use them, console or not, initialized or not ( some drivers can cold boot their hardware after all )

Yes, but the same situation could happen on a desktop. Assume I would have such a machine and boot it with serial console. According to your logic (as far as I understood it so far), I wouldn't be able to use X.

Right. The error message "Primary device is not PCI" comes from

This is unacceptable. I have a amd64 machine with serial console that I
use to run X, luckily it has only a single vga card right now.

Me too which is an other laptop.

I think the "Primary device is not PCI" error is bogus but that's a different story.
If X wants to whine about it that's fine but it shouldn't be fatal.

have fun

Version: GnuPG v1.4.7 (Darwin)


Home | Main Index | Thread Index | Old Index