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authorDan Williams <dan.j.williams@intel.com>2014-06-17 16:16:32 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-17 17:04:39 -0700
commite3d105055525d9ea9f8e9cb0db8237df3df1bb9f (patch)
tree37448f1ac032726d1e290124734a6a7a067d095d /drivers/usb/core
parent6c79fe4afcb0450bd638f6e959e512aad270ff2f (diff)
downloadlinux-stericsson-e3d105055525d9ea9f8e9cb0db8237df3df1bb9f.tar.gz
usb: fix hub-port pm_runtime_enable() vs runtime pm transitions
Commit 9262c19d14c4 "usb: disable port power control if not supported in wHubCharacteristics" gated enabling runtime pm for usb_port devices on whether the parent hub supports power control, which causes a regression. The port must still be allowed to carry out runtime pm callbacks and receive a -EAGAIN or -EBUSY result. Otherwise the usb_port device will transition to the pm error state and trigger the same for the child usb_device. Prior to the offending commit usb_hub_create_port_device() arranged for runtime pm to be disabled is dev_pm_qos_expose_flags() failed. Instead, force the default state of PM_QOS_FLAG_NO_POWER_OFF flag to be set prior to enabling runtime pm. If that policy can not be set then fail registration. Report: http://marc.info/?l=linux-usb&m=140290586301336&w=2 Fixes: 9262c19d14c4 ("usb: disable port power control if not supported in wHubCharacteristics") Reported-by: Bjørn Mork <bjorn@mork.no> Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hub.c6
-rw-r--r--drivers/usb/core/hub.h2
-rw-r--r--drivers/usb/core/port.c65
3 files changed, 54 insertions, 19 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 78c3cd20d7ae..21b99b4b4082 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1577,6 +1577,12 @@ static int hub_configure(struct usb_hub *hub,
}
}
hdev->maxchild = i;
+ for (i = 0; i < hdev->maxchild; i++) {
+ struct usb_port *port_dev = hub->ports[i];
+
+ pm_runtime_put(&port_dev->dev);
+ }
+
mutex_unlock(&usb_port_peer_mutex);
if (ret < 0)
goto fail;
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 0a7cdc0ef0a9..326308e53961 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -84,6 +84,7 @@ struct usb_hub {
* @dev: generic device interface
* @port_owner: port's owner
* @peer: related usb2 and usb3 ports (share the same connector)
+ * @req: default pm qos request for hubs without port power control
* @connect_type: port's connect type
* @location: opaque representation of platform connector location
* @status_lock: synchronize port_event() vs usb_port_{suspend|resume}
@@ -95,6 +96,7 @@ struct usb_port {
struct device dev;
struct usb_dev_state *port_owner;
struct usb_port *peer;
+ struct dev_pm_qos_request *req;
enum usb_port_connect_type connect_type;
usb_port_location_t location;
struct mutex status_lock;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 9347ade7d5fe..fe1b6d0967e3 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -68,6 +68,7 @@ static void usb_port_device_release(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
+ kfree(port_dev->req);
kfree(port_dev);
}
@@ -400,9 +401,13 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
int retval;
port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
- if (!port_dev) {
- retval = -ENOMEM;
- goto exit;
+ if (!port_dev)
+ return -ENOMEM;
+
+ port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
+ if (!port_dev->req) {
+ kfree(port_dev);
+ return -ENOMEM;
}
hub->ports[port1 - 1] = port_dev;
@@ -418,31 +423,53 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
port1);
mutex_init(&port_dev->status_lock);
retval = device_register(&port_dev->dev);
- if (retval)
- goto error_register;
+ if (retval) {
+ put_device(&port_dev->dev);
+ return retval;
+ }
+
+ /* Set default policy of port-poweroff disabled. */
+ retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
+ DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
+ if (retval < 0) {
+ device_unregister(&port_dev->dev);
+ return retval;
+ }
find_and_link_peer(hub, port1);
+ /*
+ * Enable runtime pm and hold a refernce that hub_configure()
+ * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
+ * and the hub has been fully registered (hdev->maxchild set).
+ */
pm_runtime_set_active(&port_dev->dev);
+ pm_runtime_get_noresume(&port_dev->dev);
+ pm_runtime_enable(&port_dev->dev);
+ device_enable_async_suspend(&port_dev->dev);
/*
- * Do not enable port runtime pm if the hub does not support
- * power switching. Also, userspace must have final say of
- * whether a port is permitted to power-off. Do not enable
- * runtime pm if we fail to expose pm_qos_no_power_off.
+ * Keep hidden the ability to enable port-poweroff if the hub
+ * does not support power switching.
*/
- if (hub_is_port_power_switchable(hub)
- && dev_pm_qos_expose_flags(&port_dev->dev,
- PM_QOS_FLAG_NO_POWER_OFF) == 0)
- pm_runtime_enable(&port_dev->dev);
+ if (!hub_is_port_power_switchable(hub))
+ return 0;
- device_enable_async_suspend(&port_dev->dev);
- return 0;
+ /* Attempt to let userspace take over the policy. */
+ retval = dev_pm_qos_expose_flags(&port_dev->dev,
+ PM_QOS_FLAG_NO_POWER_OFF);
+ if (retval < 0) {
+ dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
+ return 0;
+ }
-error_register:
- put_device(&port_dev->dev);
-exit:
- return retval;
+ /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
+ retval = dev_pm_qos_remove_request(port_dev->req);
+ if (retval >= 0) {
+ kfree(port_dev->req);
+ port_dev->req = NULL;
+ }
+ return 0;
}
void usb_hub_remove_port_device(struct usb_hub *hub, int port1)