From 302328c00341f1c161bfe32d085d3e6549a08f2d Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Wed, 3 Sep 2014 13:26:29 -0600 Subject: [PATCH] PCI: Preserve MPS and MRRS when applying _HPX settings Linux manages MPS and MRRS settings to keep them consistent across the PCIe fabric. BIOS doesn't participate in this Linux management, so ignore that part of any _HPX settings it supplies. Signed-off-by: Bjorn Helgaas Acked-by: Yinghai Lu --- drivers/pci/probe.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 1ff2105ba401..cb411fbb6435 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1301,6 +1301,16 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) return; } + /* + * Don't allow _HPX to change MPS or MRRS settings. We manage + * those to make sure they're consistent with the rest of the + * platform. + */ + hpp->pci_exp_devctl_and |= PCI_EXP_DEVCTL_PAYLOAD | + PCI_EXP_DEVCTL_READRQ; + hpp->pci_exp_devctl_or &= ~(PCI_EXP_DEVCTL_PAYLOAD | + PCI_EXP_DEVCTL_READRQ); + /* Initialize Device Control Register */ pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL, ~hpp->pci_exp_devctl_and, hpp->pci_exp_devctl_or); -- 2.39.5