diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2008-12-01 10:24:41 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-12-17 10:49:14 -0800 |
| commit | 24c0996a6b73e2554104961afcc8659534503e0d (patch) | |
| tree | ce806aca4dbe0b236a639a9067615594f8cdedf6 /drivers/usb/core | |
| parent | 9a9fafb89433c5fd1331bac0c84c4b321e358b42 (diff) | |
USB: skip Set-Interface(0) if already in altsetting 0
When a driver unbinds from an interface, usbcore always sends a
Set-Interface request to reinstall altsetting 0. Unforunately, quite
a few devices have buggy firmware that crashes when it receives this
request.
To avoid such problems, this patch (as1180) arranges to send the
Set-Interface request only when the interface is not already in
altsetting 0.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/driver.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 3d7793d9303..8c081308b0e 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -279,7 +279,9 @@ static int usb_unbind_interface(struct device *dev) * altsetting means creating new endpoint device entries). * When either of these happens, defer the Set-Interface. */ - if (!error && intf->dev.power.status == DPM_ON) + if (intf->cur_altsetting->desc.bAlternateSetting == 0) + ; /* Already in altsetting 0 so skip Set-Interface */ + else if (!error && intf->dev.power.status == DPM_ON) usb_set_interface(udev, intf->altsetting[0]. desc.bInterfaceNumber, 0); else |