Re: [PATCH v2] usb: core: add USB_QUIRK_NO_BOS for devices that hang on BOS descriptor

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Dec 08, 2025 at 09:58:55AM +0100, Oliver Neukum wrote:
> On 07.12.25 22:12, Greg KH wrote:
> > Ok, I can duplicate this here.  Maybe we just don't ask for the BOS
> > descriptor if no one needs/asks for it.  I can play with that later and
> > see if that helps as I'm sure this isn't going to be the only device
> > that can't handle the BOS descriptor if Windows isn't querying for it,
> > so we don't want to make a huge quirk table if we don't have to.
> 
> 1. That means we'd let lsusb crash devices. Not a good idea.

I don't think that it will crash.  hopefully not, as just reading a
descriptor after enumerated shouldn't cause that.  I'll test it out...

> 2. It is, unfortunately, possible that firmware authors simply
> script a detection sequence. That means devices would crash
> if you request a descriptor at a time when Windows would not
> request it, not just in general.
> I am afraid I need to point you at the horrible example
> of HID_ALWAYS_POLL

That is horrible, hopefully we don't have to do that here :(

thanks,

greg k-h