From eade01e4eae50ef22448eadf0bff68c8b0f99f60 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 1 Nov 2022 21:31:12 +0800 Subject: [PATCH] NFC: nxp-nci: Don't issue a zero length i2c_master_read() stable inclusion from stable-v5.10.129 commit 09f9946235308f03295fe3405a8f03d6f4c446c6 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YNDQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=09f9946235308f03295fe3405a8f03d6f4c446c6 -------------------------------- 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 Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Zheng Zengkai Reviewed-by: Wei Li --- 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 9f60e4dc5a90..3943a30053b3 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, -- GitLab