From 47b802d5d80c2fef3ccd9772d518bd602c83cea1 Mon Sep 17 00:00:00 2001 From: Chen Yu Date: Mon, 13 Jan 2020 14:07:24 +0800 Subject: [PATCH] PCI/PM: Print config space of devices before suspend When resuming from hibernation (S4, also known as "suspend to disk") on a VM, we have seen invalid config space, e.g., serial 0000:00:16.3: restoring config space at offset 0x14 (was 0x9104e000, writing 0xffffffff) To help debug problems like this, log the config space being saved before suspend, similar to the log in pci_restore_config_dword() when resuming. Link: https://lore.kernel.org/r/20200113060724.19571-1-yu.c.chen@intel.com [bhelgaas: commit log] Signed-off-by: Chen Yu Signed-off-by: Bjorn Helgaas Cc: Len Brown --- drivers/pci/pci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e87196cc1a7fb..34cde70440c32 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1372,8 +1372,11 @@ int pci_save_state(struct pci_dev *dev) { int i; /* XXX: 100% dword access ok here? */ - for (i = 0; i < 16; i++) + for (i = 0; i < 16; i++) { pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]); + pci_dbg(dev, "saving config space at offset %#x (reading %#x)\n", + i * 4, dev->saved_config_space[i]); + } dev->state_saved = true; i = pci_save_pcie_state(dev); -- 2.30.2