[PATCH v2 1/2] NFC: nxp-nci: Don't issue a zero length i2c_master_read()

From: Michael Walle
Date: Mon Jun 27 2022 - 13:06:56 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>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
---
changes since v1:
- none

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 7e451c10985d..e8f3b35afbee 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 != header.plen) {
nfc_err(&client->dev,
--
2.30.2