Re: [PATCH v3 09/14] gpu: nova-core: recover the GSP receive path from corrupt framing

[Alexandre Courbot]

On Thu Sep 3, 2026 at 12:15 PM JST, John Hubbard wrote:
<...>
> @@ -838,23 +871,26 @@ fn receive_msg<M: MessageFromGsp>(&mut self, timeout: Delta) -> Result<M>
>          let function = message.header.function();
>          let seq = message.header.sequence();
>  
> -        // Bind the result rather than returning early. The read pointer must advance past this
> -        // message on every path.
> +        // Every path must advance the read pointer past this message, including a failed decode.
>          let result = if matches!(function, Ok(f) if f == M::FUNCTION) {
> -            let (cmd, contents_1) = M::Message::from_bytes_prefix(message.contents.0).ok_or(EIO)?;
> -            let mut sbuffer = SBufferIter::new_reader([contents_1, message.contents.1]);
> -
> -            M::read(cmd, &mut sbuffer)
> -                .map_err(|e| e.into())
> -                .inspect(|_| {
> -                    if !sbuffer.is_empty() {
> -                        dev_warn!(
> -                            &self.dev,
> -                            "GSP message {:?} has unprocessed data\n",
> -                            M::FUNCTION
> -                        );
> -                    }
> -                })
> +            match M::Message::from_bytes_prefix(message.contents.0) {
> +                Some((cmd, contents_1)) => {
> +                    let mut sbuffer = SBufferIter::new_reader([contents_1, message.contents.1]);
> +
> +                    M::read(cmd, &mut sbuffer)
> +                        .map_err(|e| e.into())
> +                        .inspect(|_| {
> +                            if !sbuffer.is_empty() {
> +                                dev_warn!(
> +                                    &self.dev,
> +                                    "GSP message {:?} has unprocessed data\n",
> +                                    M::FUNCTION
> +                                );
> +                            }
> +                        })
> +                }
> +                None => Err(EIO),

This error path is the only one without a warning. How about:

    None => Err(EIO)
        .inspect_err(|_| dev_warn!(&self.dev, "GSP message {:?} too short\n", M::FUNCTION)),