Patch "PCI: Disable all BAR sizing for devices with non-compliant BARs" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

PCI: Disable all BAR sizing for devices with non-compliant BARs

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pci-disable-all-bar-sizing-for-devices-with-non-compliant-bars.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Prarit Bhargava <[email protected]>
Date: Wed, 11 May 2016 12:27:16 -0400
Subject: PCI: Disable all BAR sizing for devices with non-compliant BARs

From: Prarit Bhargava <[email protected]>

commit ad67b437f187ea818b2860524d10f878fadfdd99 upstream.

b84106b4e229 ("PCI: Disable IO/MEM decoding for devices with non-compliant BARs") disabled BAR sizing for BARs 0-5 of devices that don't comply with the PCI spec. But it didn't do anything for expansion ROM BARs, so we still try to size them, resulting in warnings like this on Broadwell-EP:

pci 0000:ff:12.0: BAR 6: failed to assign [mem size 0x00000001 pref]

Move the non-compliant BAR check from __pci_read_base() up to pci_read_bases() so it applies to the expansion ROM BAR as well as to BARs 0-5.

Note that direct callers of __pci_read_base(), like sriov_init(), will now bypass this check. We haven't had reports of devices with broken SR-IOV BARs yet.

---
 drivers/pci/probe.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -179,9 +179,6 @@ int __pci_read_base(struct pci_dev *dev,
 	u16 orig_cmd;
 	struct pci_bus_region region, inverted_region;
 
-	if (dev->non_compliant_bars)
-		return 0;
-
 	mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
 
 	/* No printks while decoding is disabled! */

@@ -322,6 +319,9 @@ static void pci_read_bases(struct pci_de
 {
 	unsigned int pos, reg;
 
+	if (dev->non_compliant_bars)
+		return;
+
 	for (pos = 0; pos < howmany; pos++) {
 		struct resource *res = &dev->resource[pos];
 		reg = PCI_BASE_ADDRESS_0 + (pos << 2);

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/pci-disable-all-bar-sizing-for-devices-with-non-compliant-bars.patch