diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2011-04-28 10:45:24 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-29 17:24:29 -0700 |
| commit | 6498d9db6d2dad4cf5deb2dd09e0816904f41ca5 (patch) | |
| tree | 68ebcb03c7d9fc1caf9205d96943ce46d0a08c4c /Documentation/usb | |
| parent | 15b2f3204a5c878c32939094775fb7349f707263 (diff) | |
USB: documentation update for the pre_reset method
This patch (as1459) updates the documentation for the pre_reset method
in struct usb_driver. When a driver is notified of an impending
reset, it must cancel all outstanding I/O and not start any new I/O
until it has been notified that the reset is complete.
As far as I know, most existing drivers that implement pre_reset do
this now. The major exceptions appear to be the SpeedTouch and
CDC-WDM drivers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/callbacks.txt | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/Documentation/usb/callbacks.txt b/Documentation/usb/callbacks.txt index bfb36b34b79..9e85846bdb9 100644 --- a/Documentation/usb/callbacks.txt +++ b/Documentation/usb/callbacks.txt @@ -95,9 +95,11 @@ pre_reset int (*pre_reset)(struct usb_interface *intf); -Another driver or user space is triggering a reset on the device which -contains the interface passed as an argument. Cease IO and save any -device state you need to restore. +A driver or user space is triggering a reset on the device which +contains the interface passed as an argument. Cease IO, wait for all +outstanding URBs to complete, and save any device state you need to +restore. No more URBs may be submitted until the post_reset method +is called. If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if you are in atomic context. |