diff mbox series

[v5,8/8] can-dev: add len8_dlc support for various CAN USB adapters

Message ID 20201109153657.17897-9-socketcan@hartkopp.net (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Introduce optional DLC element for Classic CAN | expand

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Commit Message

Oliver Hartkopp Nov. 9, 2020, 3:36 p.m. UTC 
Support the Classical CAN raw DLC functionality to send and receive DLC
values from 9 .. 15 on various Classical CAN capable USB network drivers:

- gs_usb
- pcan_usb
- pcan_usb_fd
- usb_8dev

Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 drivers/net/can/usb/gs_usb.c               |  8 ++++++--
 drivers/net/can/usb/peak_usb/pcan_usb.c    |  8 ++++++--
 drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 17 ++++++++++++-----
 drivers/net/can/usb/usb_8dev.c             |  9 ++++++---
 4 files changed, 30 insertions(+), 12 deletions(-)

Comments

Marc Kleine-Budde Nov. 9, 2020, 8:12 p.m. UTC | #1 
On 11/9/20 4:36 PM, Oliver Hartkopp wrote:
> Support the Classical CAN raw DLC functionality to send and receive DLC
> values from 9 .. 15 on various Classical CAN capable USB network drivers:
> 
> - gs_usb
> - pcan_usb
> - pcan_usb_fd
> - usb_8dev
> 
> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
> ---
>  drivers/net/can/usb/gs_usb.c               |  8 ++++++--
>  drivers/net/can/usb/peak_usb/pcan_usb.c    |  8 ++++++--
>  drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 17 ++++++++++++-----
>  drivers/net/can/usb/usb_8dev.c             |  9 ++++++---
>  4 files changed, 30 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
> index 940589667a7f..cc0c30a33335 100644
> --- a/drivers/net/can/usb/gs_usb.c
> +++ b/drivers/net/can/usb/gs_usb.c
> @@ -330,10 +330,13 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
>  			return;
>  
>  		cf->can_id = hf->can_id;
>  
>  		cf->len = can_cc_dlc2len(hf->len);
> +		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
> +						hf->len);

What about introducing a function that sets len and len8_dlc at the same time:

void can_frame_set_length(const struct can_priv *can, struct can_frame *cfd, u8
dlc);

And maybe a function that takes a canfd_frame, so that we don't need to cast....

> +
>  		memcpy(cf->data, hf->data, 8);
>  
>  		/* ERROR frames tell us information about the controller */
>  		if (hf->can_id & CAN_ERR_FLAG)
>  			gs_update_state(dev, cf);
> @@ -502,11 +505,12 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
>  	hf->channel = dev->channel;
>  
>  	cf = (struct can_frame *)skb->data;
>  
>  	hf->can_id = cf->can_id;
> -	hf->len = cf->len;
> +	hf->len = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
> +
>  	memcpy(hf->data, cf->data, cf->len);
>  
>  	usb_fill_bulk_urb(urb, dev->udev,
>  			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
>  			  hf,
> @@ -856,11 +860,11 @@ static struct gs_can *gs_make_candev(unsigned int channel,
>  	dev->can.state = CAN_STATE_STOPPED;
>  	dev->can.clock.freq = bt_const->fclk_can;
>  	dev->can.bittiming_const = &dev->bt_const;
>  	dev->can.do_set_bittiming = gs_usb_set_bittiming;
>  
> -	dev->can.ctrlmode_supported = 0;
> +	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
>  
>  	if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
>  		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
>  
>  	if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
> diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
> index ec34f87cc02c..5a8dffacc24e 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
> @@ -733,10 +733,12 @@ static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
>  
>  		cf->can_id = le16_to_cpu(tmp16) >> 5;
>  	}
>  
>  	cf->len = can_cc_dlc2len(rec_len);
> +	cf->len8_dlc = can_get_len8_dlc(mc->pdev->dev.can.ctrlmode, cf->len,
> +					rec_len);
>  
>  	/* Only first packet timestamp is a word */
>  	if (pcan_usb_decode_ts(mc, !mc->rec_ts_idx))
>  		goto decode_failed;
>  
> @@ -836,11 +838,12 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
>  	obuf[1] = 1;
>  
>  	pc = obuf + PCAN_USB_MSG_HEADER_LEN;
>  
>  	/* status/len byte */
> -	*pc = cf->len;
> +	*pc = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
> +
>  	if (cf->can_id & CAN_RTR_FLAG)
>  		*pc |= PCAN_USB_STATUSLEN_RTR;
>  
>  	/* can id */
>  	if (cf->can_id & CAN_EFF_FLAG) {
> @@ -990,11 +993,12 @@ static const struct can_bittiming_const pcan_usb_const = {
>  const struct peak_usb_adapter pcan_usb = {
>  	.name = "PCAN-USB",
>  	.device_id = PCAN_USB_PRODUCT_ID,
>  	.ctrl_count = 1,
>  	.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
> -			      CAN_CTRLMODE_BERR_REPORTING,
> +			      CAN_CTRLMODE_BERR_REPORTING |
> +			      CAN_CTRLMODE_CC_LEN8_DLC,
>  	.clock = {
>  		.freq = PCAN_USB_CRYSTAL_HZ / 2 ,
>  	},
>  	.bittiming_const = &pcan_usb_const,
>  
> 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 761e78d8e647..8020071c9067 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> @@ -492,16 +492,21 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if,
>  		if (rx_msg_flags & PUCAN_MSG_ERROR_STATE_IND)
>  			cfd->flags |= CANFD_ESI;
>  
>  		cfd->len = can_fd_dlc2len(pucan_msg_get_dlc(rm));
>  	} else {
> +		struct can_frame *cf;
> +
>  		/* CAN 2.0 frame case */
>  		skb = alloc_can_skb(netdev, (struct can_frame **)&cfd);
>  		if (!skb)
>  			return -ENOMEM;
>  
>  		cfd->len = can_cc_dlc2len(pucan_msg_get_dlc(rm));
> +		cf = (struct can_frame *)cfd;
> +		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
> +						pucan_msg_get_dlc(rm));
>  	}
>  
>  	cfd->can_id = le32_to_cpu(rm->can_id);
>  
>  	if (rx_msg_flags & PUCAN_MSG_EXT_ID)
> @@ -764,12 +769,14 @@ static int pcan_usb_fd_encode_msg(struct peak_usb_device *dev,
>  			tx_msg_flags |= PUCAN_MSG_BITRATE_SWITCH;
>  
>  		if (cfd->flags & CANFD_ESI)
>  			tx_msg_flags |= PUCAN_MSG_ERROR_STATE_IND;
>  	} else {
> +		struct can_frame *cf = (struct can_frame *)cfd;
> +
>  		/* CAND 2.0 frames */
> -		len = cfd->len;
> +		len = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
>  
>  		if (cfd->can_id & CAN_RTR_FLAG)
>  			tx_msg_flags |= PUCAN_MSG_RTR;
>  	}
>  
> @@ -1033,11 +1040,11 @@ static const struct can_bittiming_const pcan_usb_fd_data_const = {
>  
>  const struct peak_usb_adapter pcan_usb_fd = {
>  	.name = "PCAN-USB FD",
>  	.device_id = PCAN_USBFD_PRODUCT_ID,
>  	.ctrl_count = PCAN_USBFD_CHANNEL_COUNT,
> -	.ctrlmode_supported = CAN_CTRLMODE_FD |
> +	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
>  			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,

Please add the new CTRLMODE at the end, so that the list ist sorted. I don't
mind if the diff is a bit larger.

>  	.clock = {
>  		.freq = PCAN_UFD_CRYSTAL_HZ,
>  	},
>  	.bittiming_const = &pcan_usb_fd_const,
> @@ -1105,11 +1112,11 @@ static const struct can_bittiming_const pcan_usb_chip_data_const = {
>  
>  const struct peak_usb_adapter pcan_usb_chip = {
>  	.name = "PCAN-Chip USB",
>  	.device_id = PCAN_USBCHIP_PRODUCT_ID,
>  	.ctrl_count = PCAN_USBFD_CHANNEL_COUNT,
> -	.ctrlmode_supported = CAN_CTRLMODE_FD |
> +	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
>  		CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,

same here

>  	.clock = {
>  		.freq = PCAN_UFD_CRYSTAL_HZ,
>  	},
>  	.bittiming_const = &pcan_usb_chip_const,
> @@ -1177,11 +1184,11 @@ static const struct can_bittiming_const pcan_usb_pro_fd_data_const = {
>  
>  const struct peak_usb_adapter pcan_usb_pro_fd = {
>  	.name = "PCAN-USB Pro FD",
>  	.device_id = PCAN_USBPROFD_PRODUCT_ID,
>  	.ctrl_count = PCAN_USBPROFD_CHANNEL_COUNT,
> -	.ctrlmode_supported = CAN_CTRLMODE_FD |
> +	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
>  			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,

same here

>  	.clock = {
>  		.freq = PCAN_UFD_CRYSTAL_HZ,
>  	},
>  	.bittiming_const = &pcan_usb_pro_fd_const,
> @@ -1249,11 +1256,11 @@ static const struct can_bittiming_const pcan_usb_x6_data_const = {
>  
>  const struct peak_usb_adapter pcan_usb_x6 = {
>  	.name = "PCAN-USB X6",
>  	.device_id = PCAN_USBX6_PRODUCT_ID,
>  	.ctrl_count = PCAN_USBPROFD_CHANNEL_COUNT,
> -	.ctrlmode_supported = CAN_CTRLMODE_FD |
> +	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
>  			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,

same here

>  	.clock = {
>  		.freq = PCAN_UFD_CRYSTAL_HZ,
>  	},
>  	.bittiming_const = &pcan_usb_x6_const,
> diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
> index 6517aaeb4bc0..57e689cb87c9 100644
> --- a/drivers/net/can/usb/usb_8dev.c
> +++ b/drivers/net/can/usb/usb_8dev.c
> @@ -469,10 +469,12 @@ static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
>  		if (!skb)
>  			return;
>  
>  		cf->can_id = be32_to_cpu(msg->id);
>  		cf->len = can_cc_dlc2len(msg->dlc & 0xF);
> +		cf->len8_dlc = can_get_len8_dlc(priv->can.ctrlmode, cf->len,
> +						msg->dlc & 0xF);
>  
>  		if (msg->flags & USB_8DEV_EXTID)
>  			cf->can_id |= CAN_EFF_FLAG;
>  
>  		if (msg->flags & USB_8DEV_RTR)
> @@ -635,11 +637,11 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
>  
>  	if (cf->can_id & CAN_EFF_FLAG)
>  		msg->flags |= USB_8DEV_EXTID;
>  
>  	msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
> -	msg->dlc = cf->len;
> +	msg->dlc = can_get_cc_dlc(priv->can.ctrlmode, cf->len, cf->len8_dlc);
>  	memcpy(msg->data, cf->data, cf->len);
>  	msg->end = USB_8DEV_DATA_END;
>  
>  	for (i = 0; i < MAX_TX_URBS; i++) {
>  		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
> @@ -925,12 +927,13 @@ static int usb_8dev_probe(struct usb_interface *intf,
>  	priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
>  	priv->can.bittiming_const = &usb_8dev_bittiming_const;
>  	priv->can.do_set_mode = usb_8dev_set_mode;
>  	priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
>  	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
> -				      CAN_CTRLMODE_LISTENONLY |
> -				      CAN_CTRLMODE_ONE_SHOT;
> +				       CAN_CTRLMODE_LISTENONLY |
> +				       CAN_CTRLMODE_ONE_SHOT |
> +				       CAN_CTRLMODE_CC_LEN8_DLC;
>  
>  	netdev->netdev_ops = &usb_8dev_netdev_ops;
>  
>  	netdev->flags |= IFF_ECHO; /* we support local echo */
>  
> 

Marc
Oliver Hartkopp Nov. 10, 2020, 6:55 a.m. UTC | #2 
On 09.11.20 21:12, Marc Kleine-Budde wrote:
> On 11/9/20 4:36 PM, Oliver Hartkopp wrote:
>> Support the Classical CAN raw DLC functionality to send and receive DLC
>> values from 9 .. 15 on various Classical CAN capable USB network drivers:
>>
>> - gs_usb
>> - pcan_usb
>> - pcan_usb_fd
>> - usb_8dev
>>
>> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
>> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
>> ---
>>   drivers/net/can/usb/gs_usb.c               |  8 ++++++--
>>   drivers/net/can/usb/peak_usb/pcan_usb.c    |  8 ++++++--
>>   drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 17 ++++++++++++-----
>>   drivers/net/can/usb/usb_8dev.c             |  9 ++++++---
>>   4 files changed, 30 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
>> index 940589667a7f..cc0c30a33335 100644
>> --- a/drivers/net/can/usb/gs_usb.c
>> +++ b/drivers/net/can/usb/gs_usb.c
>> @@ -330,10 +330,13 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
>>   			return;
>>   
>>   		cf->can_id = hf->can_id;
>>   
>>   		cf->len = can_cc_dlc2len(hf->len);
>> +		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
>> +						hf->len);
> 
> What about introducing a function that sets len and len8_dlc at the same time:
> 
> void can_frame_set_length(const struct can_priv *can, struct can_frame *cfd, u8
> dlc);

Good idea.

I would suggest something like

u8 can_get_cc_len(const u32 ctrlmode, struct can_frame *cf, u8 dlc)

that still returns the 'len' element, so that we can replace 
can_cc_dlc2len() with can_get_cc_len() for CAN drivers that add support 
for len8_dlc.

The assignment cf->len = can_get_cc_len() fits better into the code 
which assigns cf->can_id too.

And I would stay on 'u32 ctrlmode' as ctrlmode is the parameter which is 
namely needed here. A pointer to can_priv can mean anything.

> 
> And maybe a function that takes a canfd_frame, so that we don't need to cast....

No. The len8_dlc element is from struct can_frame. When people use the 
struct canfd_frame in their driver this might have some benefits for them.
But when it comes to access the len8_dlc element this has to be casted IMO.

But with the suggested can_get_cc_len() function a needed cast could be 
put into the parameter list without adding extra code somewhere else in 
the driver.

(..)


>> @@ -1033,11 +1040,11 @@ static const struct can_bittiming_const pcan_usb_fd_data_const = {
>>   
>>   const struct peak_usb_adapter pcan_usb_fd = {
>>   	.name = "PCAN-USB FD",
>>   	.device_id = PCAN_USBFD_PRODUCT_ID,
>>   	.ctrl_count = PCAN_USBFD_CHANNEL_COUNT,
>> -	.ctrlmode_supported = CAN_CTRLMODE_FD |
>> +	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
>>   			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
> 
> Please add the new CTRLMODE at the end, so that the list ist sorted. I don't
> mind if the diff is a bit larger.
> 

I had to decide between "make the patch looking good" and "make the 
result looking good" ;-)

But I'm fine with "make the patch looking good" too. Will change that in v6.

Best regards,
Oliver
Marc Kleine-Budde Nov. 10, 2020, 7:46 a.m. UTC | #3 
On 11/10/20 7:55 AM, Oliver Hartkopp wrote:
>>> diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
>>> index 940589667a7f..cc0c30a33335 100644
>>> --- a/drivers/net/can/usb/gs_usb.c
>>> +++ b/drivers/net/can/usb/gs_usb.c
>>> @@ -330,10 +330,13 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
>>>   			return;
>>>   
>>>   		cf->can_id = hf->can_id;
>>>   
>>>   		cf->len = can_cc_dlc2len(hf->len);
>>> +		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
>>> +						hf->len);
>>
>> What about introducing a function that sets len and len8_dlc at the same time:
>>
>> void can_frame_set_length(const struct can_priv *can, struct can_frame *cfd, u8
>> dlc);
> 
> Good idea.
> 
> I would suggest something like
> 
> u8 can_get_cc_len(const u32 ctrlmode, struct can_frame *cf, u8 dlc)
> 
> that still returns the 'len' element, so that we can replace 
> can_cc_dlc2len() with can_get_cc_len() for CAN drivers that add support 
> for len8_dlc.

The regex to replace can_cc_dlc2len() with can_get_cc_len() might be simpler,
but passing the cf by reference _and_ assigning the return value to a member of
cf looks strange.

> The assignment cf->len = can_get_cc_len() fits better into the code 
> which assigns cf->can_id too.
> 
> And I would stay on 'u32 ctrlmode' as ctrlmode is the parameter which is 
> namely needed here. A pointer to can_priv can mean anything.

OK
>> And maybe a function that takes a canfd_frame, so that we don't need to cast....
> 
> No. The len8_dlc element is from struct can_frame. When people use the 
> struct canfd_frame in their driver this might have some benefits for them.
> But when it comes to access the len8_dlc element this has to be casted IMO.
> 
> But with the suggested can_get_cc_len() function a needed cast could be 
> put into the parameter list without adding extra code somewhere else in 
> the driver.

OK

Marc
Oliver Hartkopp Nov. 10, 2020, 10:18 a.m. UTC | #4 
On 10.11.20 08:46, Marc Kleine-Budde wrote:
> On 11/10/20 7:55 AM, Oliver Hartkopp wrote:

>> I would suggest something like
>>
>> u8 can_get_cc_len(const u32 ctrlmode, struct can_frame *cf, u8 dlc)
>>
>> that still returns the 'len' element, so that we can replace
>> can_cc_dlc2len() with can_get_cc_len() for CAN drivers that add support
>> for len8_dlc.
> 
> The regex to replace can_cc_dlc2len() with can_get_cc_len() might be simpler,
> but passing the cf by reference _and_ assigning the return value to a member of
> cf looks strange.

This might be a "make the patch looking good" thing too :-D

The code is now implemented even simpler and easy to follow when we 
migrate the other CAN drivers too.

But take a look on yourself. v6 is sent out.

Thanks,
Oliver
diff mbox series

Patch

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 940589667a7f..cc0c30a33335 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -330,10 +330,13 @@  static void gs_usb_receive_bulk_callback(struct urb *urb)
 			return;
 
 		cf->can_id = hf->can_id;
 
 		cf->len = can_cc_dlc2len(hf->len);
+		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
+						hf->len);
+
 		memcpy(cf->data, hf->data, 8);
 
 		/* ERROR frames tell us information about the controller */
 		if (hf->can_id & CAN_ERR_FLAG)
 			gs_update_state(dev, cf);
@@ -502,11 +505,12 @@  static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 	hf->channel = dev->channel;
 
 	cf = (struct can_frame *)skb->data;
 
 	hf->can_id = cf->can_id;
-	hf->len = cf->len;
+	hf->len = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
+
 	memcpy(hf->data, cf->data, cf->len);
 
 	usb_fill_bulk_urb(urb, dev->udev,
 			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 			  hf,
@@ -856,11 +860,11 @@  static struct gs_can *gs_make_candev(unsigned int channel,
 	dev->can.state = CAN_STATE_STOPPED;
 	dev->can.clock.freq = bt_const->fclk_can;
 	dev->can.bittiming_const = &dev->bt_const;
 	dev->can.do_set_bittiming = gs_usb_set_bittiming;
 
-	dev->can.ctrlmode_supported = 0;
+	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
 
 	if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 
 	if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
index ec34f87cc02c..5a8dffacc24e 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
@@ -733,10 +733,12 @@  static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
 
 		cf->can_id = le16_to_cpu(tmp16) >> 5;
 	}
 
 	cf->len = can_cc_dlc2len(rec_len);
+	cf->len8_dlc = can_get_len8_dlc(mc->pdev->dev.can.ctrlmode, cf->len,
+					rec_len);
 
 	/* Only first packet timestamp is a word */
 	if (pcan_usb_decode_ts(mc, !mc->rec_ts_idx))
 		goto decode_failed;
 
@@ -836,11 +838,12 @@  static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
 	obuf[1] = 1;
 
 	pc = obuf + PCAN_USB_MSG_HEADER_LEN;
 
 	/* status/len byte */
-	*pc = cf->len;
+	*pc = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
+
 	if (cf->can_id & CAN_RTR_FLAG)
 		*pc |= PCAN_USB_STATUSLEN_RTR;
 
 	/* can id */
 	if (cf->can_id & CAN_EFF_FLAG) {
@@ -990,11 +993,12 @@  static const struct can_bittiming_const pcan_usb_const = {
 const struct peak_usb_adapter pcan_usb = {
 	.name = "PCAN-USB",
 	.device_id = PCAN_USB_PRODUCT_ID,
 	.ctrl_count = 1,
 	.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
-			      CAN_CTRLMODE_BERR_REPORTING,
+			      CAN_CTRLMODE_BERR_REPORTING |
+			      CAN_CTRLMODE_CC_LEN8_DLC,
 	.clock = {
 		.freq = PCAN_USB_CRYSTAL_HZ / 2 ,
 	},
 	.bittiming_const = &pcan_usb_const,
 
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 761e78d8e647..8020071c9067 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -492,16 +492,21 @@  static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if,
 		if (rx_msg_flags & PUCAN_MSG_ERROR_STATE_IND)
 			cfd->flags |= CANFD_ESI;
 
 		cfd->len = can_fd_dlc2len(pucan_msg_get_dlc(rm));
 	} else {
+		struct can_frame *cf;
+
 		/* CAN 2.0 frame case */
 		skb = alloc_can_skb(netdev, (struct can_frame **)&cfd);
 		if (!skb)
 			return -ENOMEM;
 
 		cfd->len = can_cc_dlc2len(pucan_msg_get_dlc(rm));
+		cf = (struct can_frame *)cfd;
+		cf->len8_dlc = can_get_len8_dlc(dev->can.ctrlmode, cf->len,
+						pucan_msg_get_dlc(rm));
 	}
 
 	cfd->can_id = le32_to_cpu(rm->can_id);
 
 	if (rx_msg_flags & PUCAN_MSG_EXT_ID)
@@ -764,12 +769,14 @@  static int pcan_usb_fd_encode_msg(struct peak_usb_device *dev,
 			tx_msg_flags |= PUCAN_MSG_BITRATE_SWITCH;
 
 		if (cfd->flags & CANFD_ESI)
 			tx_msg_flags |= PUCAN_MSG_ERROR_STATE_IND;
 	} else {
+		struct can_frame *cf = (struct can_frame *)cfd;
+
 		/* CAND 2.0 frames */
-		len = cfd->len;
+		len = can_get_cc_dlc(dev->can.ctrlmode, cf->len, cf->len8_dlc);
 
 		if (cfd->can_id & CAN_RTR_FLAG)
 			tx_msg_flags |= PUCAN_MSG_RTR;
 	}
 
@@ -1033,11 +1040,11 @@  static const struct can_bittiming_const pcan_usb_fd_data_const = {
 
 const struct peak_usb_adapter pcan_usb_fd = {
 	.name = "PCAN-USB FD",
 	.device_id = PCAN_USBFD_PRODUCT_ID,
 	.ctrl_count = PCAN_USBFD_CHANNEL_COUNT,
-	.ctrlmode_supported = CAN_CTRLMODE_FD |
+	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
 			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
 	.bittiming_const = &pcan_usb_fd_const,
@@ -1105,11 +1112,11 @@  static const struct can_bittiming_const pcan_usb_chip_data_const = {
 
 const struct peak_usb_adapter pcan_usb_chip = {
 	.name = "PCAN-Chip USB",
 	.device_id = PCAN_USBCHIP_PRODUCT_ID,
 	.ctrl_count = PCAN_USBFD_CHANNEL_COUNT,
-	.ctrlmode_supported = CAN_CTRLMODE_FD |
+	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
 		CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
 	.bittiming_const = &pcan_usb_chip_const,
@@ -1177,11 +1184,11 @@  static const struct can_bittiming_const pcan_usb_pro_fd_data_const = {
 
 const struct peak_usb_adapter pcan_usb_pro_fd = {
 	.name = "PCAN-USB Pro FD",
 	.device_id = PCAN_USBPROFD_PRODUCT_ID,
 	.ctrl_count = PCAN_USBPROFD_CHANNEL_COUNT,
-	.ctrlmode_supported = CAN_CTRLMODE_FD |
+	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
 			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
 	.bittiming_const = &pcan_usb_pro_fd_const,
@@ -1249,11 +1256,11 @@  static const struct can_bittiming_const pcan_usb_x6_data_const = {
 
 const struct peak_usb_adapter pcan_usb_x6 = {
 	.name = "PCAN-USB X6",
 	.device_id = PCAN_USBX6_PRODUCT_ID,
 	.ctrl_count = PCAN_USBPROFD_CHANNEL_COUNT,
-	.ctrlmode_supported = CAN_CTRLMODE_FD |
+	.ctrlmode_supported = CAN_CTRLMODE_FD | CAN_CTRLMODE_CC_LEN8_DLC |
 			CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
 	.bittiming_const = &pcan_usb_x6_const,
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index 6517aaeb4bc0..57e689cb87c9 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -469,10 +469,12 @@  static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 		if (!skb)
 			return;
 
 		cf->can_id = be32_to_cpu(msg->id);
 		cf->len = can_cc_dlc2len(msg->dlc & 0xF);
+		cf->len8_dlc = can_get_len8_dlc(priv->can.ctrlmode, cf->len,
+						msg->dlc & 0xF);
 
 		if (msg->flags & USB_8DEV_EXTID)
 			cf->can_id |= CAN_EFF_FLAG;
 
 		if (msg->flags & USB_8DEV_RTR)
@@ -635,11 +637,11 @@  static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 
 	if (cf->can_id & CAN_EFF_FLAG)
 		msg->flags |= USB_8DEV_EXTID;
 
 	msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
-	msg->dlc = cf->len;
+	msg->dlc = can_get_cc_dlc(priv->can.ctrlmode, cf->len, cf->len8_dlc);
 	memcpy(msg->data, cf->data, cf->len);
 	msg->end = USB_8DEV_DATA_END;
 
 	for (i = 0; i < MAX_TX_URBS; i++) {
 		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
@@ -925,12 +927,13 @@  static int usb_8dev_probe(struct usb_interface *intf,
 	priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 	priv->can.bittiming_const = &usb_8dev_bittiming_const;
 	priv->can.do_set_mode = usb_8dev_set_mode;
 	priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
-				      CAN_CTRLMODE_LISTENONLY |
-				      CAN_CTRLMODE_ONE_SHOT;
+				       CAN_CTRLMODE_LISTENONLY |
+				       CAN_CTRLMODE_ONE_SHOT |
+				       CAN_CTRLMODE_CC_LEN8_DLC;
 
 	netdev->netdev_ops = &usb_8dev_netdev_ops;
 
 	netdev->flags |= IFF_ECHO; /* we support local echo */