Re: [PATCH 1/2] PCI: pciehp: Do not disable interrupt twice on suspend

From: Kai-Heng Feng
Date: Fri Jun 21 2019 - 04:53:07 EST


at 20:50, Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote:

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.

Fixes: 9c62f0bfb832 ("PCI: pciehp: Implement runtime PM callbacks")
Reported-by: Kai Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

Tested-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

---
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 6ad0d86762cb..3f8c13ddb3e8 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -248,7 +248,7 @@ 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
@@ -256,7 +256,19 @@ 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;
}

@@ -274,6 +286,7 @@ static int pciehp_resume_noirq(struct pcie_device *dev)

return 0;
}
+#endif

static int pciehp_resume(struct pcie_device *dev)
{
@@ -287,6 +300,12 @@ 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);
@@ -313,10 +332,12 @@ 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,
+#endif
.resume = pciehp_resume,
- .runtime_suspend = pciehp_suspend,
+ .runtime_suspend = pciehp_runtime_suspend,
.runtime_resume = pciehp_runtime_resume,
#endif /* PM */
};
--
2.20.1