The driver used to pass received CAN frames/skbs to the network stack with netif_rx(). In netif_rx() the skbs are queued to the local CPU. If IRQs are handled in round robin, OoO packets may occur. To avoid out-of-order reception convert the driver from netif_rx() to NAPI. For USB devices with timestamping support use the rx-offload helper can_rx_offload_queue_timestamp() for the RX, and can_rx_offload_get_echo_skb_queue_timestamp() for the TX path. Devices without timestamping support use can_rx_offload_queue_tail() for RX, and can_rx_offload_get_echo_skb_queue_tail() for the TX path. Link: https://lore.kernel.org/all/559D628C.5020100@xxxxxxxxxxxx Link: https://github.com/candle-usb/candleLight_fw/issues/166 Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-3-716e542d14d5@xxxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/usb/Kconfig | 1 + drivers/net/can/usb/gs_usb.c | 85 ++++++++++++++++++++++++++++-------- 2 files changed, 67 insertions(+), 19 deletions(-) diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig index 58fcd2b34820..d1450722cb3c 100644 --- a/drivers/net/can/usb/Kconfig +++ b/drivers/net/can/usb/Kconfig @@ -52,6 +52,7 @@ config CAN_F81604 config CAN_GS_USB tristate "Geschwister Schneider UG and candleLight compatible interfaces" + select CAN_RX_OFFLOAD help This driver supports the Geschwister Schneider and bytewerk.org candleLight compatible diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index 6caf3974e028..95b0fdb602c8 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -5,6 +5,7 @@ * Copyright (C) 2013-2016 Geschwister Schneider Technologie-, * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt). * Copyright (C) 2016 Hubert Denkmair + * Copyright (c) 2023 Pengutronix, Marc Kleine-Budde <kernel@xxxxxxxxxxxxxx> * * Many thanks to all socketcan devs! */ @@ -24,6 +25,7 @@ #include <linux/can.h> #include <linux/can/dev.h> #include <linux/can/error.h> +#include <linux/can/rx-offload.h> /* Device specific constants */ #define USB_GS_USB_1_VENDOR_ID 0x1d50 @@ -282,6 +284,8 @@ struct gs_host_frame { #define GS_MAX_TX_URBS 10 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */ #define GS_MAX_RX_URBS 30 +#define GS_NAPI_WEIGHT 32 + /* Maximum number of interfaces the driver supports per device. * Current hardware only supports 3 interfaces. The future may vary. */ @@ -295,6 +299,7 @@ struct gs_tx_context { struct gs_can { struct can_priv can; /* must be the first member */ + struct can_rx_offload offload; struct gs_usb *parent; struct net_device *netdev; @@ -506,20 +511,59 @@ static void gs_update_state(struct gs_can *dev, struct can_frame *cf) } } -static void gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb, - const struct gs_host_frame *hf) +static u32 gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb, + const struct gs_host_frame *hf) { u32 timestamp; - if (!(dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)) - return; - if (hf->flags & GS_CAN_FLAG_FD) timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us); else timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us); - gs_usb_skb_set_timestamp(dev, skb, timestamp); + if (skb) + gs_usb_skb_set_timestamp(dev, skb, timestamp); + + return timestamp; +} + +static void gs_usb_rx_offload(struct gs_can *dev, struct sk_buff *skb, + const struct gs_host_frame *hf) +{ + struct can_rx_offload *offload = &dev->offload; + int rc; + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) { + const u32 ts = gs_usb_set_timestamp(dev, skb, hf); + + rc = can_rx_offload_queue_timestamp(offload, skb, ts); + } else { + rc = can_rx_offload_queue_tail(offload, skb); + } + + if (rc) + dev->netdev->stats.rx_fifo_errors++; +} + +static unsigned int +gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb, + const struct gs_host_frame *hf) +{ + struct can_rx_offload *offload = &dev->offload; + const u32 echo_id = hf->echo_id; + unsigned int len; + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) { + const u32 ts = gs_usb_set_timestamp(dev, skb, hf); + + len = can_rx_offload_get_echo_skb_queue_timestamp(offload, echo_id, + ts, NULL); + } else { + len = can_rx_offload_get_echo_skb_queue_tail(offload, echo_id, + NULL); + } + + return len; } static void gs_usb_receive_bulk_callback(struct urb *urb) @@ -592,12 +636,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) gs_update_state(dev, cf); } - gs_usb_set_timestamp(dev, skb, hf); - - stats->rx_packets++; - stats->rx_bytes += hf->can_dlc; - - netif_rx(skb); + gs_usb_rx_offload(dev, skb, hf); } else { /* echo_id == hf->echo_id */ if (hf->echo_id >= GS_MAX_TX_URBS) { netdev_err(netdev, @@ -617,12 +656,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) } skb = dev->can.echo_skb[hf->echo_id]; - gs_usb_set_timestamp(dev, skb, hf); - stats->tx_packets++; - stats->tx_bytes += can_get_echo_skb(netdev, hf->echo_id, - NULL); - + stats->tx_bytes += gs_usb_get_echo_skb(dev, skb, hf); gs_free_tx_context(txc); atomic_dec(&dev->active_tx_urbs); @@ -641,9 +676,12 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) cf->can_id |= CAN_ERR_CRTL; cf->len = CAN_ERR_DLC; cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; - netif_rx(skb); + + gs_usb_rx_offload(dev, skb, hf); } + can_rx_offload_irq_finish(&dev->offload); + resubmit_urb: usb_fill_bulk_urb(urb, parent->udev, usb_rcvbulkpipe(parent->udev, GS_USB_ENDPOINT_IN), @@ -857,6 +895,8 @@ static int gs_can_open(struct net_device *netdev) dev->hf_size_tx = struct_size(hf, classic_can, 1); } + can_rx_offload_enable(&dev->offload); + if (!parent->active_channels) { if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) gs_usb_timestamp_init(parent); @@ -965,6 +1005,7 @@ static int gs_can_open(struct net_device *netdev) gs_usb_timestamp_stop(parent); } + can_rx_offload_disable(&dev->offload); close_candev(netdev); return rc; @@ -1037,6 +1078,8 @@ static int gs_can_close(struct net_device *netdev) dev->tx_context[rc].echo_id = GS_MAX_TX_URBS; } + can_rx_offload_disable(&dev->offload); + /* close the netdev */ close_candev(netdev); @@ -1336,6 +1379,7 @@ static struct gs_can *gs_make_candev(unsigned int channel, dev->can.data_bittiming_const = &dev->data_bt_const; } + can_rx_offload_add_manual(netdev, &dev->offload, GS_NAPI_WEIGHT); SET_NETDEV_DEV(netdev, &intf->dev); rc = register_candev(dev->netdev); @@ -1343,11 +1387,13 @@ static struct gs_can *gs_make_candev(unsigned int channel, dev_err(&intf->dev, "Couldn't register candev for channel %d (%pe)\n", channel, ERR_PTR(rc)); - goto out_free_candev; + goto out_can_rx_offload_del; } return dev; +out_can_rx_offload_del: + can_rx_offload_del(&dev->offload); out_free_candev: free_candev(dev->netdev); return ERR_PTR(rc); @@ -1356,6 +1402,7 @@ static struct gs_can *gs_make_candev(unsigned int channel, static void gs_destroy_candev(struct gs_can *dev) { unregister_candev(dev->netdev); + can_rx_offload_del(&dev->offload); free_candev(dev->netdev); } -- 2.40.1
