[PATCH 3/4][SRU][OEM-B] UBUNTU: SAUCE: PCI: pciehp: Do not disable interrupt twice on suspend

[AceLan Kao]

From: Mika Westerberg <mika.westerberg at linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/1849269

We try to keep PCIe hotplug ports runtime suspended when entering system
suspend. Due to the fact that the PCIe portdrv sets NEVER_SKIP driver PM
flag the PM core always calls system suspend/resume hooks even if the
device is left runtime suspended. Since PCIe hotplug driver re-uses the
same function for both it ends up disabling hotplug interrupt twice and
the second time following is printed:

  pciehp 0000:03:01.0:pcie204: pcie_do_write_cmd: no response from device

Prevent this from happening by checking whether the device is already
runtime suspended when system suspend hook is called.

Link: https://patchwork.kernel.org/patch/11089971/
Fixes: 9c62f0bfb832 ("PCI: pciehp: Implement runtime PM callbacks")
Reported-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
Tested-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
---
 drivers/pci/hotplug/pciehp_core.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 55cf9783703da..20cfa94273029 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -269,7 +269,7 @@ static bool pme_is_native(struct pcie_device *dev)
 	return pcie_ports_native || host->native_pme;
 }
 
-static int pciehp_suspend(struct pcie_device *dev)
+static void pciehp_disable_interrupt(struct pcie_device *dev)
 {
 	/*
 	 * Disable hotplug interrupt so that it does not trigger
@@ -277,7 +277,19 @@ static int pciehp_suspend(struct pcie_device *dev)
 	 */
 	if (pme_is_native(dev))
 		pcie_disable_interrupt(get_service_data(dev));
+}
 
+#ifdef CONFIG_PM_SLEEP
+static int pciehp_suspend(struct pcie_device *dev)
+{
+	/*
+	 * If the port is already runtime suspended we can keep it that
+	 * way.
+	 */
+	if (dev_pm_smart_suspend_and_suspended(&dev->port->dev))
+		return 0;
+
+	pciehp_disable_interrupt(dev);
 	return 0;
 }
 
@@ -295,6 +307,7 @@ static int pciehp_resume_noirq(struct pcie_device *dev)
 
 	return 0;
 }
+#endif
 
 static int pciehp_resume(struct pcie_device *dev)
 {
@@ -308,6 +321,12 @@ static int pciehp_resume(struct pcie_device *dev)
 	return 0;
 }
 
+static int pciehp_runtime_suspend(struct pcie_device *dev)
+{
+	pciehp_disable_interrupt(dev);
+	return 0;
+}
+
 static int pciehp_runtime_resume(struct pcie_device *dev)
 {
 	struct controller *ctrl = get_service_data(dev);
@@ -334,10 +353,12 @@ static struct pcie_port_service_driver hpdriver_portdrv = {
 	.remove		= pciehp_remove,
 
 #ifdef	CONFIG_PM
+#ifdef	CONFIG_PM_SLEEP
 	.suspend	= pciehp_suspend,
 	.resume_noirq	= pciehp_resume_noirq,
 	.resume		= pciehp_resume,
-	.runtime_suspend = pciehp_suspend,
+#endif
+	.runtime_suspend = pciehp_runtime_suspend,
 	.runtime_resume	= pciehp_runtime_resume,
 #endif	/* PM */
 };
-- 
2.17.1