Prevent a recovery result of:
"hub 3-0:1.0: Cannot enable port 1. Maybe the USB cable is bad?"
Once a populated port has been resumed, do not allow it to be suspended
again until it has gone through a recovery cycle (reset_resume). It has
been observed that bouncing power without an intervening recovery
results in the endpoint device failing to reconnect.
Force an autosuspend timeout and a recovery of the port before allowing
power to be removed again.
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/hub.h | 1 +
drivers/usb/core/port.c | 23 ++++++++++++++++++++++-
2 files changed, 23 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 733d4ef53683..64958ff59ad4 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -87,6 +87,7 @@ struct usb_port {
struct usb_device *child;
struct device dev;
struct dev_state *port_owner;
+ struct work_struct ratelimit_work;
enum usb_port_connect_type connect_type;
u8 portnum;
};
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 977e5b137b79..4f63c49df162 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -97,9 +97,24 @@ static void usb_port_device_release(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
+ cancel_work_sync(&port_dev->ratelimit_work);
kfree(port_dev);
}
+static void pm_ping_child(struct work_struct *w)
+{
+ struct usb_port *port_dev;
+ struct usb_device *udev;
+
+ port_dev = container_of(w, typeof(*port_dev), ratelimit_work);
+ udev = usb_port_get_child(port_dev);
+ if (udev) {
+ pm_runtime_get_sync(&udev->dev);
+ pm_runtime_put_autosuspend(&udev->dev);
+ }
+ usb_port_put_child(udev);
+}
+
#ifdef CONFIG_PM_RUNTIME
static int usb_port_runtime_resume(struct device *dev)
{
@@ -117,9 +132,13 @@ static int usb_port_runtime_resume(struct device *dev)
if (test_bit(port1, hub->poweroff_bits))
retval = usb_set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
- /* no child? we're done recovering this port */
+ /* no child? we're done recovering this port, otherwise try to
+ * recover the device connection to rate limit power toggling
+ */
if (!port_dev->child)
usb_clear_port_poweroff(hub, port1);
+ else
+ schedule_work(&port_dev->ratelimit_work);
usb_autopm_put_interface(intf);
return retval;
@@ -156,6 +175,7 @@ static int usb_port_runtime_suspend(struct device *dev)
int port1 = port_dev->portnum;
int retval;
+ flush_work(&port_dev->ratelimit_work);
if (!hub)
return -EINVAL;
@@ -251,6 +271,7 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
port_dev->dev.parent = hub->intfdev;
port_dev->dev.groups = port_dev_group;
port_dev->dev.type = &usb_port_device_type;
+ INIT_WORK(&port_dev->ratelimit_work, pm_ping_child);
dev_set_name(&port_dev->dev, "port%d", port1);
retval = device_register(&port_dev->dev);
--
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