summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-06-23 00:03:00 +0000
committerJohannes Weiner <hannes@cmpxchg.org>2016-06-23 00:03:00 +0000
commit90fbe8d8441dfa4fc00ac1bc49bc695ec2659b8e (patch)
tree4c7359244e6fadc4ab02df2485e59cea30e9242c
parent609c6b1a674832062a82928ff4f25521ed0e8ccb (diff)
pci: test for unexpectedly disabled bridgesv4.7-rc4-mmotm-2016-06-22-16-21
The all-ones value is not just a "device didn't exist" case, it's also potentially a quite valid value, so not restoring it would be wrong. What *would* be interesting is to hear where the bad values came from in the first place. It sounds like the device state is saved after the PCI bus controller in front of the device has been crapped on, resulting in the PCI config cycles never reaching the device at all. Something along this patch (together with suspend/resume debugging output) migth help pinpoint it. But it really sounds like something totally brokenly turned off the PCI bridge (some ACPI shutdown crud? I wouldn't be entirely surprised) Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--drivers/pci/pci.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d2035b284449..d104238d099d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1067,6 +1067,15 @@ static void pci_restore_pcix_state(struct pci_dev *dev)
int pci_save_state(struct pci_dev *dev)
{
int i;
+ u32 val;
+
+ /* Unable to read PCI device/manufacturer state? Something is seriously wrong! */
+ if (pci_read_config_dword(dev, 0, &val) || val == 0xffffffff) {
+ printk("Broken read from PCI device %s\n", pci_name(dev));
+ WARN_ON(1);
+ return -1;
+ }
+
/* XXX: 100% dword access ok here? */
for (i = 0; i < 16; i++)
pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);