[PATCH 4.9 13/29] NFC: nxp-nci: Dont issue a zero length i2c_master_read()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Michael Walle <michael@walle.cc>

commit eddd95b9423946aaacb55cac6a9b2cea8ab944fc upstream.

There are packets which doesn't have a payload. In that case, the second
i2c_master_read() will have a zero length. But because the NFC
controller doesn't have any data left, it will NACK the I2C read and
-ENXIO will be returned. In case there is no payload, just skip the
second i2c master read.

Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nfc/nxp-nci/i2c.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/nfc/nxp-nci/i2c.c
+++ b/drivers/nfc/nxp-nci/i2c.c
@@ -180,6 +180,9 @@ static int nxp_nci_i2c_nci_read(struct n
 	memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header,
 	       NCI_CTRL_HDR_SIZE);
 
+	if (!header.plen)
+		return 0;
+
 	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 	if (r != header.plen) {
 		nfc_err(&client->dev,