Re: [RFT PATCH] xhci: Fix memory leak when caching protocol extended capability PSI tables

[Mathias Nyman]

On 8.1.2020 17.40, Greg KH wrote:
> On Wed, Jan 08, 2020 at 05:17:30PM +0200, Mathias Nyman wrote:
> > xhci driver assumed that xHC controllers have at most one custom
> > supported speed table (PSI) for all usb 3.x ports.
> > Memory was allocated for one PSI table under the xhci hub structure.
> >
> > Turns out this is not the case, some controllers have a separate
> > "supported protocol capability" entry with a PSI table for each port.
> > This means each usb3 port can in theory support different custom speeds.
>
> Is there a "max" number of port capabilities that can happen?  Or this
> this truely dynamic?

Almost truly dynamic, each capability points to the next, last points to 0

But we can't have more "supported protocol capabilities" than xHC ports.
(MaxPorts value in xHC HCSPARAMS1 register)

> > +	for (i = 0; i < xhci->num_port_caps; i++) {
> > +		kfree(xhci->port_caps[i].psi);
> > +		xhci->port_caps[i].psi = NULL;
> > +	}
>
> Nit, no need to set to NULL here :)

Thanks, will remove that

-Mathias