Re: [PATCH 08/12] can: kvaser_usb_leaf: Fix improved state not being reported

[Jimmy Assarsson <extja@xxxxxxxxxx>]

On 5/16/22 15:47, Anssi Hannula wrote:
> The tested 0bfd:0017 Kvaser Memorator Professional HS/HS FW 2.0.50 and
> 0bfd:0124 Kvaser Mini PCI Express 2xHS FW 4.18.778 do not seem to send
> any unsolicited events when error counters decrease or when the device
> transitions from ERROR_PASSIVE to ERROR_ACTIVE (or WARNING).
>
> This causes the interface to e.g. indefinitely stay in the ERROR_PASSIVE
> state.
>
> Fix that by asking for chip state (inc. counters) event every 0.5 secs
> when error counters are non-zero.
>
> Since the driver seems to be prepared for non-error-counter devices
> (!KVASER_USB_HAS_TXRX_ERRORS) as well, also always poll in ERROR_PASSIVE
> even if the counters show zero.
>
> Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
> Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxxxxxx>

Looks good to me.
Tested-by: Jimmy Assarsson <extja@xxxxxxxxxx>

> ---
>   drivers/net/can/usb/kvaser_usb/kvaser_usb.h   |  7 +++
>   .../net/can/usb/kvaser_usb/kvaser_usb_core.c  | 18 +++++-
>   .../net/can/usb/kvaser_usb/kvaser_usb_leaf.c  | 58 +++++++++++++++++++
>   3 files changed, 80 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
> index f1bea13a3829..70aa7a9ed35b 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
> @@ -107,6 +107,9 @@ struct kvaser_usb_net_priv {
>   	struct can_priv can;
>   	struct can_berr_counter bec;
>   
> +	/* subdriver-specific data */
> +	void *sub_priv;
> +
>   	struct kvaser_usb *dev;
>   	struct net_device *netdev;
>   	int channel;
> @@ -128,6 +131,8 @@ struct kvaser_usb_net_priv {
>    *
>    * @dev_setup_endpoints:	setup USB in and out endpoints
>    * @dev_init_card:		initialize card
> + * @dev_init_channel:		initialize channel
> + * @dev_remove_channel:		uninitialize channel
>    * @dev_get_software_info:	get software info
>    * @dev_get_software_details:	get software details
>    * @dev_get_card_info:		get card info
> @@ -149,6 +154,8 @@ struct kvaser_usb_dev_ops {
>   				    struct can_berr_counter *bec);
>   	int (*dev_setup_endpoints)(struct kvaser_usb *dev);
>   	int (*dev_init_card)(struct kvaser_usb *dev);
> +	int (*dev_init_channel)(struct kvaser_usb_net_priv *priv);
> +	void (*dev_remove_channel)(struct kvaser_usb_net_priv *priv);
>   	int (*dev_get_software_info)(struct kvaser_usb *dev);
>   	int (*dev_get_software_details)(struct kvaser_usb *dev);
>   	int (*dev_get_card_info)(struct kvaser_usb *dev);
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> index a8d72fb8291a..6a1ebdd9ba85 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> @@ -645,6 +645,9 @@ static void kvaser_usb_remove_interfaces(struct kvaser_usb *dev)
>   		if (!dev->nets[i])
>   			continue;
>   
> +		if (dev->ops->dev_remove_channel)
> +			dev->ops->dev_remove_channel(dev->nets[i]);
> +
>   		free_candev(dev->nets[i]->netdev);
>   	}
>   }
> @@ -712,17 +715,26 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev,
>   
>   	dev->nets[channel] = priv;
>   
> +	if (dev->ops->dev_init_channel) {
> +		err = dev->ops->dev_init_channel(priv);
> +		if (err)
> +			goto err;
> +	}
> +
>   	err = register_candev(netdev);
>   	if (err) {
>   		dev_err(&dev->intf->dev, "Failed to register CAN device\n");
> -		free_candev(netdev);
> -		dev->nets[channel] = NULL;
> -		return err;
> +		goto err;
>   	}
>   
>   	netdev_dbg(netdev, "device registered\n");
>   
>   	return 0;
> +
> +err:
> +	free_candev(netdev);
> +	dev->nets[channel] = NULL;
> +	return err;
>   }
>   
>   static int kvaser_usb_probe(struct usb_interface *intf,
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
> index 5f27c00179c1..abb681808a28 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
> @@ -21,6 +21,7 @@
>   #include <linux/types.h>
>   #include <linux/units.h>
>   #include <linux/usb.h>
> +#include <linux/workqueue.h>
>   
>   #include <linux/can.h>
>   #include <linux/can/dev.h>
> @@ -56,6 +57,7 @@
>   #define CMD_RX_EXT_MESSAGE		14
>   #define CMD_TX_EXT_MESSAGE		15
>   #define CMD_SET_BUS_PARAMS		16
> +#define CMD_GET_CHIP_STATE		19
>   #define CMD_CHIP_STATE_EVENT		20
>   #define CMD_SET_CTRL_MODE		21
>   #define CMD_RESET_CHIP			24
> @@ -375,6 +377,12 @@ struct kvaser_usb_err_summary {
>   	};
>   };
>   
> +struct kvaser_usb_net_leaf_priv {
> +	struct kvaser_usb_net_priv *net;
> +
> +	struct delayed_work chip_state_req_work;
> +};
> +
>   static const struct can_bittiming_const kvaser_usb_leaf_bittiming_const = {
>   	.name = "kvaser_usb",
>   	.tseg1_min = KVASER_USB_TSEG1_MIN,
> @@ -757,6 +765,16 @@ static int kvaser_usb_leaf_simple_cmd_async(struct kvaser_usb_net_priv *priv,
>   	return err;
>   }
>   
> +static void kvaser_usb_leaf_chip_state_req_work(struct work_struct *work)
> +{
> +	struct kvaser_usb_net_leaf_priv *leaf =
> +		container_of(work, struct kvaser_usb_net_leaf_priv,
> +			     chip_state_req_work.work);
> +	struct kvaser_usb_net_priv *priv = leaf->net;
> +
> +	kvaser_usb_leaf_simple_cmd_async(priv, CMD_GET_CHIP_STATE);
> +}
> +
>   static void
>   kvaser_usb_leaf_rx_error_update_can_state(struct kvaser_usb_net_priv *priv,
>   					const struct kvaser_usb_err_summary *es,
> @@ -828,6 +846,7 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev,
>   	struct sk_buff *skb;
>   	struct net_device_stats *stats;
>   	struct kvaser_usb_net_priv *priv;
> +	struct kvaser_usb_net_leaf_priv *leaf;
>   	enum can_state old_state, new_state;
>   
>   	if (es->channel >= dev->nchannels) {
> @@ -837,6 +856,7 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev,
>   	}
>   
>   	priv = dev->nets[es->channel];
> +	leaf = priv->sub_priv;
>   	stats = &priv->netdev->stats;
>   
>   	/* Update all of the CAN interface's state and error counters before
> @@ -853,6 +873,14 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev,
>   	kvaser_usb_leaf_rx_error_update_can_state(priv, es, &tmp_cf);
>   	new_state = priv->can.state;
>   
> +	/* If there are errors, request status updates periodically as we do
> +	 * not get automatic notifications of improved state.
> +	 */
> +	if (new_state < CAN_STATE_BUS_OFF &&
> +	    (es->rxerr || es->txerr || new_state == CAN_STATE_ERROR_PASSIVE))
> +		schedule_delayed_work(&leaf->chip_state_req_work,
> +				      msecs_to_jiffies(500));
> +
>   	skb = alloc_can_err_skb(priv->netdev, &cf);
>   	if (!skb) {
>   		stats->rx_dropped++;
> @@ -1312,10 +1340,13 @@ static int kvaser_usb_leaf_start_chip(struct kvaser_usb_net_priv *priv)
>   
>   static int kvaser_usb_leaf_stop_chip(struct kvaser_usb_net_priv *priv)
>   {
> +	struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
>   	int err;
>   
>   	reinit_completion(&priv->stop_comp);
>   
> +	cancel_delayed_work(&leaf->chip_state_req_work);
> +
>   	err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_STOP_CHIP,
>   					      priv->channel);
>   	if (err)
> @@ -1362,6 +1393,31 @@ static int kvaser_usb_leaf_init_card(struct kvaser_usb *dev)
>   	return 0;
>   }
>   
> +static int kvaser_usb_leaf_init_channel(struct kvaser_usb_net_priv *priv)
> +{
> +	struct kvaser_usb_net_leaf_priv *leaf;
> +
> +	leaf = devm_kzalloc(&priv->dev->intf->dev, sizeof(*leaf), GFP_KERNEL);
> +	if (!leaf)
> +		return -ENOMEM;
> +
> +	leaf->net = priv;
> +	INIT_DELAYED_WORK(&leaf->chip_state_req_work,
> +			  kvaser_usb_leaf_chip_state_req_work);
> +
> +	priv->sub_priv = leaf;
> +
> +	return 0;
> +}
> +
> +static void kvaser_usb_leaf_remove_channel(struct kvaser_usb_net_priv *priv)
> +{
> +	struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
> +
> +	if (leaf)
> +		cancel_delayed_work_sync(&leaf->chip_state_req_work);
> +}
> +
>   static int kvaser_usb_leaf_set_bittiming(struct net_device *netdev)
>   {
>   	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> @@ -1463,6 +1519,8 @@ const struct kvaser_usb_dev_ops kvaser_usb_leaf_dev_ops = {
>   	.dev_get_berr_counter = kvaser_usb_leaf_get_berr_counter,
>   	.dev_setup_endpoints = kvaser_usb_leaf_setup_endpoints,
>   	.dev_init_card = kvaser_usb_leaf_init_card,
> +	.dev_init_channel = kvaser_usb_leaf_init_channel,
> +	.dev_remove_channel = kvaser_usb_leaf_remove_channel,
>   	.dev_get_software_info = kvaser_usb_leaf_get_software_info,
>   	.dev_get_software_details = NULL,
>   	.dev_get_card_info = kvaser_usb_leaf_get_card_info,