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 <lukas@xxxxxxxxx>
---
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 a5bd3b055c0e..3e73b12ed656 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);
--
2.17.1
