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 <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 8d92bc22
......@@ -461,9 +461,19 @@ int
pci_restore_state(struct pci_dev *dev)
int i;
for (i = 0; i < 16; i++)
pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);
int val;
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,
return 0;
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