From 874b3251113a1e2cbe79c24994dc03fe4fe4b99b Mon Sep 17 00:00:00 2001
From: Keith Busch <keith.busch@intel.com>
Date: Thu, 20 Sep 2018 10:27:07 -0600
Subject: [PATCH] PCI: portdrv: Restore PCI config state on slot reset
Git-commit: 874b3251113a1e2cbe79c24994dc03fe4fe4b99b
Patch-mainline: v4.20-rc1
References: bsc#1142623

The port's config space may be cleared after a link reset, which wipes out
the bridge's bus and memory windows.  Restore the config space that was
saved during probe so we can access downstream devices.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/pcie/portdrv_pci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index 23a5a0c2c3fe..17256733fa43 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -146,6 +146,13 @@ static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
 	return PCI_ERS_RESULT_CAN_RECOVER;
 }
 
+static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
+{
+	pci_restore_state(dev);
+	pci_save_state(dev);
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
 {
 	return PCI_ERS_RESULT_RECOVERED;
@@ -185,6 +192,7 @@ static const struct pci_device_id port_pci_ids[] = { {
 
 static const struct pci_error_handlers pcie_portdrv_err_handler = {
 	.error_detected = pcie_portdrv_error_detected,
+	.slot_reset = pcie_portdrv_slot_reset,
 	.mmio_enabled = pcie_portdrv_mmio_enabled,
 	.resume = pcie_portdrv_err_resume,
 };
-- 
2.16.4