This is a note to let you know that I've just added the patch titled NFC: nxp-nci: Don't issue a zero length i2c_master_read() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfc-nxp-nci-don-t-issue-a-zero-length-i2c_master_read.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From eddd95b9423946aaacb55cac6a9b2cea8ab944fc Mon Sep 17 00:00:00 2001 From: Michael Walle <michael@xxxxxxxx> Date: Mon, 27 Jun 2022 19:06:42 +0200 Subject: NFC: nxp-nci: Don't issue a zero length i2c_master_read() From: Michael Walle <michael@xxxxxxxx> 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@xxxxxxxx> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -178,6 +178,9 @@ static int nxp_nci_i2c_nci_read(struct n 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, Patches currently in stable-queue which might be from michael@xxxxxxxx are queue-4.14/nfc-nxp-nci-don-t-issue-a-zero-length-i2c_master_read.patch