diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c index 34bf022bb724498396bd0c525339ecbe7f6c4692..fbcd5c2b13aeb1a7358a9d656f97ffa1b46bf13b 100644 --- a/drivers/net/dsa/qca/qca8k-8xxx.c +++ b/drivers/net/dsa/qca/qca8k-8xxx.c @@ -111,7 +111,16 @@ static void qca8k_rw_reg_ack_handler(struct dsa_switch *ds, struct sk_buff *skb) command = get_unaligned_le32(&mgmt_ethhdr->command); cmd = FIELD_GET(QCA_HDR_MGMT_CMD, command); + len = FIELD_GET(QCA_HDR_MGMT_LENGTH, command); + /* Special case for len of 15 as this is the max value for len and needs to + * be increased before converting it from word to dword. + */ + if (len == 15) + len++; + + /* We can ignore odd value, we always round up them in the alloc function. */ + len *= sizeof(u16); /* Make sure the seq match the requested packet */ if (get_unaligned_le32(&mgmt_ethhdr->seq) == mgmt_eth_data->seq) @@ -158,17 +167,33 @@ static struct sk_buff *qca8k_alloc_mdio_header(enum mdio_cmd cmd, u32 reg, u32 * if (!skb) return NULL; - /* Max value for len reg is 15 (0xf) but the switch actually return 16 byte - * Actually for some reason the steps are: - * 0: nothing - * 1-4: first 4 byte - * 5-6: first 12 byte - * 7-15: all 16 byte + /* Hdr mgmt length value is in step of word size. + * As an example to process 4 byte of data the correct length to set is 2. + * To process 8 byte 4, 12 byte 6, 16 byte 8... + * + * Odd values will always return the next size on the ack packet. + * (length of 3 (6 byte) will always return 8 bytes of data) + * + * This means that a value of 15 (0xf) actually means reading/writing 32 bytes + * of data. + * + * To correctly calculate the length we devide the requested len by word and + * round up. + * On the ack function we can skip the odd check as we already handle the + * case here. + */ + real_len = DIV_ROUND_UP(len, sizeof(u16)); + + /* We check if the result len is odd and we round up another time to + * the next size. (length of 3 will be increased to 4 as switch will always + * return 8 bytes) */ - if (len == 16) - real_len = 15; - else - real_len = len; + if (real_len % sizeof(u16) != 0) + real_len++; + + /* Max reg value is 0xf(15) but switch will always return the next size (32 byte) */ + if (real_len == 16) + real_len--; skb_reset_mac_header(skb); skb_set_network_header(skb, skb->len);