From 469e764c4a3c7260b353b7bc1bd56c283cb001da Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@wunner.de>
Date: Thu, 19 Jul 2018 17:27:54 -0500
Subject: [PATCH] PCI: pciehp: Obey compulsory command delay after resume
Git-commit: 469e764c4a3c7260b353b7bc1bd56c283cb001da
Patch-mainline: v4.19-rc1
References: FATE#326145
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@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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);
--
2.19.2