From 469e764c4a3c7260b353b7bc1bd56c283cb001da Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 19 Jul 2018 17:27:54 -0500 Subject: [PATCH] PCI: pciehp: Obey compulsory command delay after resume Upon resume from system sleep, the Slot Control register is written via: pci_pm_resume_noirq() pci_pm_default_resume_early() pci_restore_state() pci_restore_pcie_state() PCIe r4.0, sec 6.7.3.2 says that after "issuing a write transaction that targets any portion of the Port's Slot Control register, [...] software must wait for [the] command to complete before issuing the next command". pciehp currently fails to enforce that rule after the above-mentioned write. Fix it. (Moving restoration of the Slot Control register to pciehp doesn't seem to make sense because the other PCIe hotplug drivers may need it as well.) Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index a5bd3b0..3e73b12 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -284,6 +284,10 @@ static int pciehp_resume_noirq(struct pcie_device *dev) struct controller *ctrl = get_service_data(dev); struct slot *slot = ctrl->slot; + /* pci_restore_state() just wrote to the Slot Control register */ + ctrl->cmd_started = jiffies; + ctrl->cmd_busy = true; + /* clear spurious events from rediscovery of inserted card */ if (slot->state == ON_STATE || slot->state == BLINKINGOFF_STATE) pcie_clear_hotplug_events(ctrl); -- 2.7.4