[PATCH 4.4 73/96] PCI: Apply _HPX settings only to relevant devices

Greg Kroah-Hartman
2017-11-28T10:23:22Z

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit 977509f7c5c6fb992ffcdf4291051af343b91645 ]

Previously we didn't check the type of device before trying to apply Type 1
(PCI-X) or Type 2 (PCIe) Setting Records from _HPX.

We don't support PCI-X Setting Records, so this was harmless, but the
warning was useless.

We do support PCIe Setting Records, and we didn't check whether a device
was PCIe before applying settings. I don't think anything bad happened on
non-PCIe devices because pcie_capability_clear_and_set_word(),
pcie_cap_has_lnkctl(), etc., would fail before doing any harm. But it's
ugly to depend on those internals.

Check the device type before attempting to apply Type 1 and Type 2 Setting
Records (Type 0 records are applicable to PCI, PCI-X, and PCIe devices).

A side benefit is that this prevents useless "not supported" warnings when
a BIOS supplies a Type 1 (PCI-X) Setting Record and we try to apply it to
every single device:

pci 0000:00:00.0: PCI-X settings not supported

After this patch, we'll get the warning only when a BIOS supplies a Type 1
record and we have a PCI-X device to which it should be applied.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=187731
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/probe.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1414,8 +1414,16 @@ static void program_hpp_type0(struct pci

static void program_hpp_type1(struct pci_dev *dev, struct hpp_type1 *hpp)
{
- if (hpp)
- dev_warn(&dev->dev, "PCI-X settings not supported\n");
+ int pos;
+
+ if (!hpp)
+ return;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
+ if (!pos)
+ return;
+
+ dev_warn(&dev->dev, "PCI-X settings not supported\n");
}

static bool pcie_root_rcb_set(struct pci_dev *dev)
@@ -1441,6 +1449,9 @@ static void program_hpp_type2(struct pci
if (!hpp)
return;

+ if (!pci_is_pcie(dev))
+ return;
+
if (hpp->revision > 1) {
dev_warn(&dev->dev, "PCIe settings rev %d not supported\n",
hpp->revision);