diff options
Diffstat (limited to 'Documentation/usb')
-rw-r--r-- | Documentation/usb/power-management.txt | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt index ad642615ad4c..8817368203d6 100644 --- a/Documentation/usb/power-management.txt +++ b/Documentation/usb/power-management.txt | |||
@@ -423,15 +423,16 @@ an URB had completed too recently. | |||
423 | 423 | ||
424 | External suspend calls should never be allowed to fail in this way, | 424 | External suspend calls should never be allowed to fail in this way, |
425 | only autosuspend calls. The driver can tell them apart by checking | 425 | only autosuspend calls. The driver can tell them apart by checking |
426 | udev->auto_pm; this flag will be set to 1 for internal PM events | 426 | the PM_EVENT_AUTO bit in the message.event argument to the suspend |
427 | (autosuspend or autoresume) and 0 for external PM events. | 427 | method; this bit will be set for internal PM events (autosuspend) and |
428 | clear for external PM events. | ||
428 | 429 | ||
429 | Many of the ingredients in the autosuspend framework are oriented | 430 | Many of the ingredients in the autosuspend framework are oriented |
430 | towards interfaces: The usb_interface structure contains the | 431 | towards interfaces: The usb_interface structure contains the |
431 | pm_usage_cnt field, and the usb_autopm_* routines take an interface | 432 | pm_usage_cnt field, and the usb_autopm_* routines take an interface |
432 | pointer as their argument. But somewhat confusingly, a few of the | 433 | pointer as their argument. But somewhat confusingly, a few of the |
433 | pieces (usb_mark_last_busy() and udev->auto_pm) use the usb_device | 434 | pieces (i.e., usb_mark_last_busy()) use the usb_device structure |
434 | structure instead. Drivers need to keep this straight; they can call | 435 | instead. Drivers need to keep this straight; they can call |
435 | interface_to_usbdev() to find the device structure for a given | 436 | interface_to_usbdev() to find the device structure for a given |
436 | interface. | 437 | interface. |
437 | 438 | ||