When khubd has evaluated a poweroff bit it needs to guarantee that the
powered on state stays stable for the duration of its evaluation. So,
hold a pm_runtime reference and synchronize the state of port while
evaluating the port status/change registers.
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/hub.c | 35 ++++++++++++++++++++++++++++++-----
1 files changed, 30 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 6f2cf4672942..028f1c061119 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4652,10 +4652,37 @@ static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
return connect_change;
}
+static struct usb_port *get_port_pm_sync(struct usb_hub *hub, int port1)
+{
+ struct usb_device *hdev = hub->hdev;
+
+ if (port1 <= hdev->maxchild) {
+ struct usb_port *port_dev = hub->ports[port1 - 1];
+
+ pm_runtime_get_noresume(&port_dev->dev);
+ pm_runtime_barrier(&port_dev->dev);
+ return port_dev;
+ }
+
+ return NULL;
+}
+
+static void put_port_pm_sync(struct usb_port *port_dev)
+{
+ if (!port_dev)
+ return;
+
+ pm_runtime_put_sync(&port_dev->dev);
+}
+
+#define for_each_port_pm_sync(i, p, h) \
+ for (i = 1; (p = get_port_pm_sync(h, i)); i++, put_port_pm_sync(p))
+
static void hub_events(void)
{
struct list_head *tmp;
struct usb_device *hdev;
+ struct usb_port *port_dev;
struct usb_interface *intf;
struct usb_hub *hub;
struct device *hub_dev;
@@ -4737,7 +4764,7 @@ static void hub_events(void)
}
/* deal with port status changes */
- for (i = 1; i <= hdev->maxchild; i++) {
+ for_each_port_pm_sync(i, port_dev, hub) {
if (test_bit(i, hub->busy_bits))
continue;
connect_change = test_bit(i, hub->change_bits);
@@ -4776,8 +4803,7 @@ static void hub_events(void)
* Works at least with mouse driver.
*/
if (!(portstatus & USB_PORT_STAT_ENABLE)
- && !connect_change
- && hub->ports[i - 1]->child) {
+ && !connect_change && port_dev->child) {
dev_err (hub_dev,
"port %i "
"disabled by hub (EMI?), "
@@ -4839,8 +4865,7 @@ static void hub_events(void)
*/
if (hub_port_warm_reset_required(hub, portstatus)) {
int status;
- struct usb_device *udev =
- hub->ports[i - 1]->child;
+ struct usb_device *udev = port_dev->child;
dev_dbg(hub_dev, "warm reset port %d\n", i);
if (!udev || !(portstatus &
--
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