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Commit 04d9c1a1 authored by Dave Jones's avatar Dave Jones Committed by Greg Kroah-Hartman
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[PATCH] PCI: Improve PCI config space writeback 



At least one laptop blew up on resume from suspend with a black screen due
to a lack of this patch.  By only writing back config space that is
different, we minimise the possibility of accidents like this.

Signed-off-by: default avatarDave Jones <davej@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8d92bc22

drivers/pci/pci.c

+13 −3
Original line number Diff line number Diff line
@@ -461,9 +461,19 @@ int 
pci_restore_state(struct pci_dev *dev)

{

	int i;

	int val;



	for (i = 0; i < 16; i++)

		pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);

	for (i = 0; i < 16; i++) {

		pci_read_config_dword(dev, i * 4, &val);

		if (val != dev->saved_config_space[i]) {

			printk(KERN_DEBUG "PM: Writing back config space on "

				"device %s at offset %x (was %x, writing %x)\n",

				pci_name(dev), i,

				val, (int)dev->saved_config_space[i]);

			pci_write_config_dword(dev,i * 4,

				dev->saved_config_space[i]);

		}

	}

	pci_restore_msi_state(dev);

	pci_restore_msix_state(dev);

	return 0;