Re: [PATCH] missing pci_disable_device()

[Jeff Garzik]

Well, the kexec folks have a bit of a point (but not IMO a strong one).

Overall to be friendly with firmware and multi-driver situations we 
should try and _restore_ the state of the PCI device prior to 
pci_enable_device(), when pci_disable_device() is called.

Some situations -- namely BIOS/ACPI/SMM and kexec -- really do care 
about the state of the hardware at shutdown time.  Other situations are 
purely Linux problems, like what Jens ran into a month or more ago:
* IDE driver loads, including on legacy addresses
* modprobe ata_piix
* 	pci_enable_device() on a running device
*	notice, according to pci_request_regions, that regions are busy
*	pci_disable_device()
*	IDE suddenly stops working because we disabled IO/MEM


However, with regards to bus-mastering bit specifically, it is 
considered a Real Good Idea on a lot of the hardware I mess with to 
disable busmastering when you shut down the hardware.

	Jeff



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/