diff options
Diffstat (limited to 'drivers/nfc/st21nfca/i2c.c')
| -rw-r--r-- | drivers/nfc/st21nfca/i2c.c | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/drivers/nfc/st21nfca/i2c.c b/drivers/nfc/st21nfca/i2c.c index e29351ca7dd1..48f8e23fc321 100644 --- a/drivers/nfc/st21nfca/i2c.c +++ b/drivers/nfc/st21nfca/i2c.c @@ -53,6 +53,8 @@ /* 2 bytes crc + EOF */ #define ST21NFCA_FRAME_TAILROOM 3 +#define IS_START_OF_FRAME(buf) (buf[0] == ST21NFCA_SOF_EOF && \ + buf[1] == 0) #define ST21NFCA_HCI_I2C_DRIVER_NAME "st21nfca_hci_i2c" @@ -361,6 +363,7 @@ static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy, { int r, i; u8 len; + u8 buf[ST21NFCA_HCI_LLC_MAX_PAYLOAD]; struct i2c_client *client = phy->i2c_dev; if (phy->current_read_len < ARRAY_SIZE(len_seq)) { @@ -373,7 +376,7 @@ static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy, */ r = 0; for (i = 0; i < ARRAY_SIZE(wait_tab) && r <= 0; i++) { - r = i2c_master_recv(client, skb_put(skb, len), len); + r = i2c_master_recv(client, buf, len); if (r < 0) msleep(wait_tab[i]); } @@ -383,8 +386,28 @@ static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy, return -EREMOTEIO; } - if (memchr(skb->data + 2, ST21NFCA_SOF_EOF, - skb->len - 2) != NULL) { + /* + * The first read sequence does not start with SOF. + * Data is corrupeted so we drop it. + */ + if (!phy->current_read_len && buf[0] != ST21NFCA_SOF_EOF) { + skb_trim(skb, 0); + phy->current_read_len = 0; + return -EIO; + } else if (phy->current_read_len && + IS_START_OF_FRAME(buf)) { + /* + * Previous frame transmission was interrupted and + * the frame got repeated. + * Received frame start with ST21NFCA_SOF_EOF + 00. + */ + skb_trim(skb, 0); + phy->current_read_len = 0; + } + + memcpy(skb_put(skb, len), buf, len); + + if (skb->data[skb->len - 1] == ST21NFCA_SOF_EOF) { phy->current_read_len = 0; return st21nfca_hci_i2c_repack(skb); } |