Re: [PATCH 7/7] USB: cdc-acm: always claim data interface

On Mon, Mar 22, 2021 at 11:46:47AM +0100, Oliver Neukum wrote:

Am Donnerstag, den 18.03.2021, 16:52 +0100 schrieb Johan Hovold:

quoted

Make sure to always claim the data interface and bail out if it's
already bound to another driver or isn't authorised.

Hi,

Thanks for the fixes. All previous ones are good work.
this one is problematic I am afraid.


acm_probe() has a test for the availability of the interface:

	if (!combined_interfaces && usb_interface_claimed(data_interface)) {
		/* valid in this context */
		dev_dbg(&intf->dev, "The data interface isn't available\n");
		return -EBUSY;
	}

That check is ancient. BKL still existed. If you want to remove it
and do proper error handling, that would be good. But if you do
error handling, the check has to go, too.

Thanks, this bit can go indeed. But note that it's simply because it's
now redundant.

I'll send a v2.

Johan