Re: [PATCH wireless-next 2/2] wifi: wfx: fix error code on unsupported firmware

["Sverdlin, Alexander" <alexander.sverdlin@siemens.com>]

Hi Jérôme,

On Mon, 2026-09-07 at 08:59 +0200, Jérôme Pouiller wrote:
> > > The 'secure link' feature is not supported by upstream (the reference
> > > code relies on mbedTLS to implement it, which is not an option for the
> > > Linux kernel).
> > > 
> > > If the firmware enforce the 'secure link' feature, wfx_probe() exits
> > > early. However, err still holds the value returned by the previous call
> > > to wait_for_completion_timeout(), which is the number of jiffies left
> > > before the timeout, hence strictly positive (the zero case is handled
> > > just above).
> > > 
> > > wfx_probe() therefore returns a positive value. The bus probe functions
> > > forward it as-is and the driver core negates it (see really_probe()).
> > > The device does not get bound, which is the expected outcome, but the
> > > reported error code is a meaningless negative jiffies count instead of
> >                                         ^^^^^^^^
> > minor: I suppose it should have read "positive"
> 
> I mean, really_probe() inverts the value:
> 
>     /*
>      * Return probe errors as positive values so that the callers
>      * can distinguish them from other errors.
>      */
>     ret = -ret;
>     goto probe_failed;
> 
> So, the jiffies count become negative

you are right, I didn't realize the above explains the driver core ;-)
Thanks for explanation and sorry for the noise!

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com