Re: [PATCH] can: peak_usb: Add support of loopback mode to the PCAN-USB FD family

[Marc Kleine-Budde]

On 30.09.2026 15:34:48, Stéphane Grosjean wrote:
> From: Stéphane Grosjean <s.grosjean@xxxxxxxxxxxxxx>
>
> This commit adds loopback mode support for all PEAK-System USB-to-CAN FD
> interfaces.
>
> The implementation follows the same approach as the peak_pciefd driver.
> The only difference is local echo handling: on USB devices, transmit
> confirmations are provided through USB write acknowledgments rather than
> through the reception of a controller-generated loopback frame.
>
> Signed-off-by: Stéphane Grosjean <s.grosjean@xxxxxxxxxxxxxx>
> ---
>  drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> index 5840623662af..a00ce1f52341 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> @@ -934,6 +934,12 @@ static int pcan_usb_fd_encode_msg(struct peak_usb_device *dev,
>  	if (dev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
>  		tx_msg_flags |= PUCAN_MSG_SINGLE_SHOT;
>
> +	/* Request controller loopback and mark the frame as self-received,
> +	 * matching the behavior of the peak_pciefd driver.
> +	 */
> +	if (dev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> +		tx_msg_flags |= PUCAN_MSG_LOOPED_BACK | PUCAN_MSG_SELF_RECEIVE;
> +
>  	tx_msg->flags = cpu_to_le16(tx_msg_flags);
>  	tx_msg->channel_dlc = PUCAN_MSG_CHANNEL_DLC(dev->ctrl_idx, dlc);
>  	memcpy(tx_msg->d, cfd->data, cfd->len);
> @@ -1266,7 +1272,7 @@ const struct peak_usb_adapter pcan_usb_fd = {
>  	.ctrlmode_supported = CAN_CTRLMODE_FD |
>  			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
>  			CAN_CTRLMODE_ONE_SHOT | CAN_CTRLMODE_CC_LEN8_DLC |
> -			CAN_CTRLMODE_BERR_REPORTING,
> +			CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LOOPBACK,

Can you keep the CAN_CTRLMODE sorted by their value?

Please make an incremental patch for the CAN_CTRLMODE_BERR_REPORTING,
I'll squash that...and add CAN_CTRLMODE_LOOPBACK in the appropriate
place.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

Attachment: signature.asc
Description: PGP signature