[PATCH 2/2] NFC: nxp-nci: Don't issue a zero length i2c_master_read()

From: Michael Walle
Date: Sun Jun 26 2022 - 15:43:00 EST


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@xxxxxxxx>
---
drivers/nfc/nxp-nci/i2c.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
index 9c80d5a6d56b..c9361b5249b7 100644
--- a/drivers/nfc/nxp-nci/i2c.c
+++ b/drivers/nfc/nxp-nci/i2c.c
@@ -162,6 +162,9 @@ static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,

skb_put_data(*skb, (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 < 0) {
nfc_err(&client->dev, "I2C receive error %pe\n", ERR_PTR(r));
--
2.30.2