Re: [RFC PATCH 7/7] drm/pci: Defer initialization of secondary graphics devices until switcheroo is ready

On Mon, Aug 20, 2012 at 04:36:40PM +0100, Matthew Garrett wrote:

On Mon, Aug 20, 2012 at 10:31:04AM -0500, Seth Forshee wrote:

...

• /*

• * For secondary graphics devices shouldn't be initialized
  

• * until the handler and primary graphics device have been
  

• * registered with vga_switcheroo.
  

• *
  

• * FIXME: Is vga_default_device() reliable enough for this
  

• * purpose?
  

• *
  

• * FIXME: If vga_switcheroo is disabled secondary devices
  

• * never gets initialized. Is this okay? Maybe it is, since
  

• * we can't switch to the secondary GPU anyway.
  

• */
  

Won't this break the multiple cards with independent outputs case?

Yes, if they don't have a switcheroo handler. I only have experience with one such machine, which had optimus graphics. My recollection is that it did have a switcheroo handler, which was only capable of controlling power to the discrete card.