diff options
Diffstat (limited to 'drivers/net/can/rx-offload.c')
| -rw-r--r-- | drivers/net/can/rx-offload.c | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c index b44bad669d15..fd7a7500ffeb 100644 --- a/drivers/net/can/rx-offload.c +++ b/drivers/net/can/rx-offload.c @@ -116,7 +116,29 @@ static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b) return cb_b->timestamp - cb_a->timestamp; } -static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n) +/** + * can_rx_offload_offload_one() - Read one CAN frame from HW + * @offload: pointer to rx_offload context + * @n: number of mailbox to read + * + * The task of this function is to read a CAN frame from mailbox @n + * from the device and return the mailbox's content as a struct + * sk_buff. + * + * If the struct can_rx_offload::skb_queue exceeds the maximal queue + * length (struct can_rx_offload::skb_queue_len_max) or no skb can be + * allocated, the mailbox contents is discarded by reading it into an + * overflow buffer. This way the mailbox is marked as free by the + * driver. + * + * Return: A pointer to skb containing the CAN frame on success. + * + * NULL if the mailbox @n is empty. + * + * ERR_PTR() in case of an error + */ +static struct sk_buff * +can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n) { struct sk_buff *skb = NULL; u32 timestamp; @@ -153,8 +175,8 @@ int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, u64 pen continue; skb = can_rx_offload_offload_one(offload, i); - if (!skb) - break; + if (IS_ERR_OR_NULL(skb)) + continue; __skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare); } @@ -184,7 +206,13 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload) struct sk_buff *skb; int received = 0; - while ((skb = can_rx_offload_offload_one(offload, 0))) { + while (1) { + skb = can_rx_offload_offload_one(offload, 0); + if (IS_ERR(skb)) + continue; + if (!skb) + break; + skb_queue_tail(&offload->skb_queue, skb); received++; } @@ -203,8 +231,10 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload, unsigned long flags; if (skb_queue_len(&offload->skb_queue) > - offload->skb_queue_len_max) - return -ENOMEM; + offload->skb_queue_len_max) { + kfree_skb(skb); + return -ENOBUFS; + } cb = can_rx_offload_get_cb(skb); cb->timestamp = timestamp; @@ -246,8 +276,10 @@ int can_rx_offload_queue_tail(struct can_rx_offload *offload, struct sk_buff *skb) { if (skb_queue_len(&offload->skb_queue) > - offload->skb_queue_len_max) - return -ENOMEM; + offload->skb_queue_len_max) { + kfree_skb(skb); + return -ENOBUFS; + } skb_queue_tail(&offload->skb_queue, skb); can_rx_offload_schedule(offload); |