Re: [PATCH] add PCI ROMs to sysfs

[Vojtech Pavlik <vojtech@suse.cz>]

On Fri, Jul 30, 2004 at 02:53:25PM -0700, Jon Smirl wrote:
> Here's another grungy thing I needed to do to PCI. Multi-headed video
> cards don't really implement independent PCI devices even though they
> look like independent devices. I've heard that this behavior is needed
> for MS Windows compatibility.
> 
> I'm missing a PCI call to claim ownership for the secondary device
> without also causing a second instance of my driver to be loaded.
> Here's the code I'm using, what's the right way to do this?
> 
> struct pci_dev *secondary;
> /* check the next function on the same card */
> secondary = pci_find_slot(dev->pdev->bus->number, dev->pdev->devfn +
> 1);
> if (secondary) {
> 	/* check if class is secondary video */
> 	if (secondary->class == 0x038000) {
> 		DRM_DEBUG("registering secondary video head\n");
> 		/* This code is need to bind the driver to the secondary device */
> 		/* There is no direct pci call to do this, there should be one */
> 		secondary->dev.driver = dev->pdev->dev.driver;
> 		device_bind_driver(&secondary->dev);
> 		/* dev->pdev->driver is not filled until after probe completes */
> 		secondary->driver = to_pci_driver(dev->pdev->dev.driver);
> 		pci_dev_get(secondary);
> 	}
> }

You can do that, but where is the problem with your probe function being
called twice - once for each of the devices? You should be able to sort
out which one is which rather easily.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR