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USB: Set wakeup bits for all children hubs.

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This patch takes care of the race condition between the Function Wake
Device Notification and the auto-suspend timeout for this situation:

Roothub
  | (U3)
hub A
  | (U3)
hub B
  | (U3)
device C

When device C signals a resume, the xHCI driver will set the wakeup_bits
for the roothub port that hub A is attached to.  However, since USB 3.0
hubs do not set a link state change bit on device-initiated resume, hub
A will not indicate a port event when polled.  Without this patch, khubd
will notice the wakeup-bits are set for the roothub port, it will resume
hub A, and then it will poll the events bits for hub A and notice that
nothing has changed.  Then it will be suspended after 2 seconds.

Change hub_activate() to look at the port link state for each USB 3.0
hub port, and set hub->change_bits if the link state is U0, indicating
the device has finished resume.  Change the resume function called by
hub_events(), hub_handle_remote_wakeup(), to check the link status
for resume instead of just the port's wakeup_bits.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This commit is contained in:
Sarah Sharp 2012-01-24 11:46:50 -08:00
parent 4ee823b83b
commit 72937e1e34
1 changed files with 15 additions and 7 deletions
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22
drivers/usb/core/hub.c
View file

@ -853,12 +853,19 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
set_bit(port1, hub->change_bits);
} else if (portstatus & USB_PORT_STAT_ENABLE) {
bool port_resumed = (portstatus &
USB_PORT_STAT_LINK_STATE) ==
USB_SS_PORT_LS_U0;
/* The power session apparently survived the resume.
* If there was an overcurrent or suspend change
* (i.e., remote wakeup request), have khubd
* take care of it.
* take care of it. Look at the port link state
* for USB 3.0 hubs, since they don't have a suspend
* change bit, and they don't set the port link change
* bit on device-initiated resume.
*/
if (portchange)
if (portchange || (hub_is_superspeed(hub->hdev) &&
port_resumed))
set_bit(port1, hub->change_bits);
} else if (udev->persist_enabled) {
@ -3509,7 +3516,7 @@ done:
/* Returns 1 if there was a remote wakeup and a connect status change. */
static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
u16 portchange)
u16 portstatus, u16 portchange)
{
struct usb_device *hdev;
struct usb_device *udev;
@ -3524,8 +3531,8 @@ static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
} else {
if (!udev || udev->state != USB_STATE_SUSPENDED ||
!test_and_clear_bit(udev->portnum,
hub->wakeup_bits))
(portstatus & USB_PORT_STAT_LINK_STATE) !=
USB_SS_PORT_LS_U0)
return 0;
}
@ -3638,7 +3645,7 @@ static void hub_events(void)
if (test_bit(i, hub->busy_bits))
continue;
connect_change = test_bit(i, hub->change_bits);
wakeup_change = test_bit(i, hub->wakeup_bits);
wakeup_change = test_and_clear_bit(i, hub->wakeup_bits);
if (!test_and_clear_bit(i, hub->event_bits) &&
!connect_change && !wakeup_change)
continue;
@ -3681,7 +3688,8 @@ static void hub_events(void)
}
}
if (hub_handle_remote_wakeup(hub, i, portchange))
if (hub_handle_remote_wakeup(hub, i,
portstatus, portchange))
connect_change = 1;
if (portchange & USB_PORT_STAT_C_OVERCURRENT) {