The Read Completion Boundary bit must only be set on a device or endpoint if
it is set on the upstream bridge.
Fixes: 7a1562d4f ("PCI: Apply _HPX Link Control settings to all devices with a link")
Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
---
drivers/pci/probe.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)
Changes from v1:
* Check if we have a upstream bridge to not trip on a NULL pointer
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ab00267..716c5cf 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1439,6 +1439,19 @@ static void program_hpp_type1(struct pci_dev *dev, struct hpp_type1 *hpp)
dev_warn(&dev->dev, "PCI-X settings not supported\n");
}
+static bool pcie_get_upstream_rcb(struct pci_dev *dev)
+{
+ struct pci_dev *bridge = pci_upstream_bridge(dev);
+ u16 lnkctl;
+
+ if (!bridge)
+ return false;
+
+ pcie_capability_read_word(bridge, PCI_EXP_LNKCTL, &lnkctl);
+
+ return lnkctl & PCI_EXP_LNKCTL_RCB;
+}
+
static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
{
int pos;
@@ -1468,9 +1481,21 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
~hpp->pci_exp_devctl_and, hpp->pci_exp_devctl_or);
/* Initialize Link Control Register */
- if (pcie_cap_has_lnkctl(dev))
+ if (pcie_cap_has_lnkctl(dev)) {
+ bool us_rcb;
+ u16 clear;
+ u16 set;
+
+ us_rcb = pcie_get_upstream_rcb(dev);
+
+ clear = ~hpp->pci_exp_lnkctl_and;
+ set = hpp->pci_exp_lnkctl_or;
+ if (!us_rcb)
+ set &= ~PCI_EXP_LNKCTL_RCB;
+
pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
- ~hpp->pci_exp_lnkctl_and, hpp->pci_exp_lnkctl_or);
+ clear, set);
+ }
/* Find Advanced Error Reporting Enhanced Capability */
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
--
1.8.5.6
--
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