Re: Fwd: Patch to control VGA bus routing and active VGA device.

[Jesse Barnes <jbarnes@sgi.com>]

On Thursday, January 27, 2005 1:59 am, Jon Smirl wrote:
> Another item I need to add is generating an initial hotplug event for
> each secondary card. This event has to happen even if there is a card
> specific driver loaded. The event will be used to run the reset
> program needed by secondary cards.

Makes sense, having hotplug events would be nice.  I've got a standalone bios 
emulator (based on the X int10 library) that I hope to open source soon, we 
could use that as a starting piont for the reset app.

+static void vga_enable(struct pci_dev *pdev, unsigned int enable)
...
+ outb(~0x01 & inb(0x3C3),  0x3C3);
+ outb(~0x08 & inb(0x46e8), 0x46e8);
+ outb(~0x01 & inb(0x102),  0x102);
+ pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_VGA_ACTIVE;
+ if (pdev == vga_active)
+  vga_active = NULL;
+ bridge_no(pdev);

Those ins and outs won't work on all platforms unless they have a base address 
(assigned by arch code) associated with them.  But then again, I suppose if a 
platform supports more than one legacy I/O space, it also supports multiple 
active VGAs, so maybe this enable/disable code isn't needed for them...

Jesse