Re: [PATCH v2 3/5] firmware: arm_scmi: Add message dump traces for bad and unexpected replies

[Sudeep Holla]

On Mon, Mar 25, 2024 at 08:46:18PM +0000, Cristian Marussi wrote:
> Trace also late-timed-out, out-of-order and unexpected/spurious messages.
> 
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
>  drivers/firmware/arm_scmi/driver.c  | 10 ++++++++++
>  drivers/firmware/arm_scmi/mailbox.c |  4 +++-
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> index 7fc1c5b1a2a4..207ed1a52d69 100644
> --- a/drivers/firmware/arm_scmi/driver.c
> +++ b/drivers/firmware/arm_scmi/driver.c
> @@ -861,6 +861,9 @@ scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr)
>  			"Message for %d type %d is not expected!\n",
>  			xfer_id, msg_type);
>  		spin_unlock_irqrestore(&minfo->xfer_lock, flags);
> +
> +		scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNEXPECTED);
> +
>  		return xfer;
>  	}
>  	refcount_inc(&xfer->users);
> @@ -885,6 +888,9 @@ scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr)
>  		dev_err(cinfo->dev,
>  			"Invalid message type:%d for %d - HDR:0x%X  state:%d\n",
>  			msg_type, xfer_id, msg_hdr, xfer->state);
> +
> +		scmi_bad_message_trace(cinfo, msg_hdr, MSG_INVALID);
> +
>  		/* On error the refcount incremented above has to be dropped */
>  		__scmi_xfer_put(minfo, xfer);
>  		xfer = ERR_PTR(-EINVAL);
> @@ -921,6 +927,9 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo,
>  	if (IS_ERR(xfer)) {
>  		dev_err(dev, "failed to get free message slot (%ld)\n",
>  			PTR_ERR(xfer));
> +
> +		scmi_bad_message_trace(cinfo, msg_hdr, MSG_NOMEM);
> +
>  		scmi_clear_channel(info, cinfo);
>  		return;
>  	}
> @@ -1040,6 +1049,7 @@ void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv)
>  		break;
>  	default:
>  		WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type);
> +		scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNKNOWN);
>  		break;
>  	}
>  }
> diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
> index b8d470417e8f..fb0824af7180 100644
> --- a/drivers/firmware/arm_scmi/mailbox.c
> +++ b/drivers/firmware/arm_scmi/mailbox.c
> @@ -56,7 +56,9 @@ static void rx_callback(struct mbox_client *cl, void *m)
>  	 */
>  	if (cl->knows_txdone && !shmem_channel_free(smbox->shmem)) {
>  		dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
> -		return;
> +		return scmi_bad_message_trace(smbox->cinfo,
> +				     shmem_read_header(smbox->shmem),
> +				     MSG_MBOX_SPURIOUS);

>From previous patch, IIUC scmi_bad_message_trace is a void func and doesn't
return anything. Did you not get any build error/warning for this ?

-- 
Regards,
Sudeep