Re: [PATCH] cdc-ether: clean packet filter upon probe

[Oliver Neukum <oneukum@suse.de>]

On Thu, 2014-08-14 at 13:11 +0200, Bjørn Mork wrote:
> Oliver Neukum <oneukum@suse.de> writes:
> 
> > There are devices that don't do reset all the way. So the packet filter should
> > be set to a sane initial value. Failure to do so leads to intermittent failures
> > of DHCP on some systems under some conditions.
> >
> > Signed-off-by: Oliver Neukum <oneukum@suse.de>
> > ---
> >  drivers/net/usb/cdc_ether.c | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
> > index 9ea4bfe..2a32d91 100644
> > --- a/drivers/net/usb/cdc_ether.c
> > +++ b/drivers/net/usb/cdc_ether.c
> > @@ -341,6 +341,22 @@ next_desc:
> >  		usb_driver_release_interface(driver, info->data);
> >  		return -ENODEV;
> >  	}
> > +
> > +	/* Some devices don't initialise properly. In particular
> > +	 * the packet filter is not reset. There are devices that
> > +	 * don't do reset all the way. So the packet filter should
> > +	 * be set to a sane initial value.
> > +	 */
> > +	usb_control_msg(dev->udev,
> > +			usb_sndctrlpipe(dev->udev, 0),
> > +			USB_CDC_SET_ETHERNET_PACKET_FILTER,
> > +			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
> > +			USB_CDC_PACKET_TYPE_ALL_MULTICAST | USB_CDC_PACKET_TYPE_DIRECTED | USB_CDC_PACKET_TYPE_BROADCAST,
> > +			intf->cur_altsetting->desc.bInterfaceNumber,
> > +			NULL,
> > +			0,
> > +			USB_CTRL_SET_TIMEOUT
> > +		);
> >  	return 0;
> >  
> >  bad_desc:
> 
> Hmm, the usbnet_generic_cdc_bind() function is used by the vendor
> specific zaurus and rndis_host drivers as well.  Are we sure the
> USB_CDC_SET_ETHERNET_PACKET_FILTER message is supported by all devices
> supported by these drivers?

Support for this request is mandatory.

	Regards
		Oliver