4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aleksandr Bezzubikov <zuban32s@xxxxxxxxx> commit 48b79a14505349a29b3e20f03619ada9b33c4b17 upstream. An SHPC may generate MSIs to notify software about slot or controller events (SHPC spec r1.0, sec 4.7). A PCI device can only generate an MSI if it has bus mastering enabled. Enable bus mastering if the bridge contains an SHPC that uses MSI for event notifications. Signed-off-by: Aleksandr Bezzubikov <zuban32s@xxxxxxxxx> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Marcel Apfelbaum <marcel@xxxxxxxxxx> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/hotplug/shpchp_hpc.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/pci/hotplug/shpchp_hpc.c +++ b/drivers/pci/hotplug/shpchp_hpc.c @@ -1062,6 +1062,8 @@ int shpc_init(struct controller *ctrl, s if (rc) { ctrl_info(ctrl, "Can't get msi for the hotplug controller\n"); ctrl_info(ctrl, "Use INTx for the hotplug controller\n"); + } else { + pci_set_master(pdev); } rc = request_irq(ctrl->pci_dev->irq, shpc_isr, IRQF_SHARED,