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 <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
This commit is contained in:
Bjorn Helgaas 2014-09-03 13:26:29 -06:00
parent ca0647e08a
commit 302328c003

View file

@ -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);