From 04d9c1a1100b6bdeffa7e1bfc30080bdac28e183 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 18 Apr 2006 21:06:51 -0700 Subject: [PATCH] [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: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2329f941a0dc..d2520451f36b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -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, + dev->saved_config_space[i]); + } + } pci_restore_msi_state(dev); pci_restore_msix_state(dev); return 0; -- 2.30.2