On Tue, Jul 10, 2012 at 09:09:53AM +0530, Arun Raghavan wrote: > After suspend and resume, the values of these registers seem to change > from what they were at suspend time, potentially preventing the actual > output lines from being enabled post-resume. This saves relevant state > at suspend and restores it when resumed. > > This is at least required on the MacBook Pro 8.2 when the Intel GPU is > manually selected in GRUB config before the kernel is loaded. I've got a couple of problems with this. The first is that the backlight update_status callback isn't an appropriate place to do this. Adding suspend/resume ops for the pnp_driver would be better. But the more serious concern is whether or not its safe to simply restore the register values. I know that the reverse engineering work done on the gmux has revealed a particular sequence for selecting the active GPU. A brute force restoration of the registers disregards this sequencing, which doesn't seem like a good idea. Seth -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
