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

[Sverdlin, Alexander]

Hi Jérôme,

On Sun, 2026-09-06 at 22:47 +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"

> an errno.
> 
> Return -EOPNOTSUPP, as already done a few lines above when the firmware
> API version is not supported.
> 
> Copilot reviewed the code and wrote some parts of the log.
> 
> Reported-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/cc4de4e40e3ca50e7288be2b9067802576567c25.camel@xxxxxxxxxxx/
> Assisted-by: Copilot:claude-opus-5
> Signed-off-by: Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx>

Reviewed-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxxxx>

> ---
>  drivers/net/wireless/silabs/wfx/main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
> index b6fd9d4c1f5fc..16d5b51f6f03a 100644
> --- a/drivers/net/wireless/silabs/wfx/main.c
> +++ b/drivers/net/wireless/silabs/wfx/main.c
> @@ -411,6 +411,7 @@ int wfx_probe(struct wfx_dev *wdev)
>  
>  	if (wdev->hw_caps.link_mode == SEC_LINK_ENFORCED) {
>  		dev_err(wdev->dev, "chip require secure_link, but can't negotiate it\n");
> +		err = -EOPNOTSUPP;
>  		goto irq_unsubscribe;
>  	}

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com