Replace ->can_dlc with ->len

can_frame.can_dlc has been deprecated in favour of can_frame.len and as
a new driver, this needs to stick to the new convention.

Also include the ugliest backwards hack #define I've ever written to
make this compile on Linux <= 5.10 which is currently LTS.

diff --git a/module/elmcan.c b/module/elmcan.c
index f358a46dafe86f3950be8a2ea15d8bfcb529746f..e8f163f81f1c38cc4056344c1203d82a92cce8e7 100644 (file)
--- a/module/elmcan.c
+++ b/module/elmcan.c
@@ -50,6 +50,11 @@ MODULE_AUTHOR("Max Staudt <max-linux@enpas.org>");
 #define N_DEVELOPMENT 29
 #endif
 
+/* Compatibility for Linux < 5.11 */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5,11,0)
+#define len can_dlc
+#endif
+
 #define ELM327_NAPI_WEIGHT 4
 
 #define ELM327_SIZE_RXBUF 256
@@ -483,7 +488,7 @@ static int elm327_parse_frame(struct elmcan *elm, size_t len)
         */
 
        /* Read CAN data length */
-       frame->can_dlc = (hex_to_bin(elm->rxbuf[datastart - 2]) << 0);
+       frame->len = (hex_to_bin(elm->rxbuf[datastart - 2]) << 0);
 
        /* Read CAN ID */
        if (frame->can_id & CAN_EFF_FLAG) {
@@ -511,13 +516,13 @@ static int elm327_parse_frame(struct elmcan *elm, size_t len)
         * Note: RTR frames have a DLC, but no actual payload.
         */
        if (!(frame->can_id & CAN_RTR_FLAG) &&
-           (hexlen < frame->can_dlc * 3 + datastart)) {
+           (hexlen < frame->len * 3 + datastart)) {
                /* Incomplete frame.
                 * Probably the ELM327's RS232 TX buffer was full.
                 * Emit an error frame and exit.
                 */
                frame->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
-               frame->can_dlc = CAN_ERR_DLC;
+               frame->len = CAN_ERR_DLC;
                frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
                elm327_feed_frame_to_netdev(elm, skb);
 
@@ -530,7 +535,7 @@ static int elm327_parse_frame(struct elmcan *elm, size_t len)
        }
 
        /* Parse the data nibbles. */
-       for (i = 0; i < frame->can_dlc; i++) {
+       for (i = 0; i < frame->len; i++) {
                frame->data[i] = (hex_to_bin(elm->rxbuf[datastart + 3*i]) << 4)
                               | (hex_to_bin(elm->rxbuf[datastart + 3*i + 1]));
        }
@@ -634,7 +639,7 @@ static void elm327_handle_prompt(struct elmcan *elm)
                        /* Send a regular CAN data frame */
                        int i;
 
-                       for (i = 0; i < frame->can_dlc; i++) {
+                       for (i = 0; i < frame->len; i++) {
                                sprintf(&local_txbuf[2 * i], "%02X",
                                        frame->data[i]);
                        }
@@ -871,7 +876,7 @@ static netdev_tx_t elmcan_netdev_start_xmit(struct sk_buff *skb,
        spin_unlock(&elm->lock);
 
        dev->stats.tx_packets++;
-       dev->stats.tx_bytes += frame->can_dlc;
+       dev->stats.tx_bytes += frame->len;
 
        can_led_event(dev, CAN_LED_EVENT_TX);