| Message ID | 20220626194243.4059870-2-michael@walle.cc (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [1/2] NFC: nxp-nci: check return code of i2c_master_recv() | expand |
On 26/06/2022 21:42, Michael Walle wrote: > 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> Best regards, Krzysztof
Am 2022-06-26 21:51, schrieb Krzysztof Kozlowski: > On 26/06/2022 21:42, Michael Walle wrote: >> 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> Thanks, I'll reorder the patches in the next version otherwise there will likely be a conflict. That should work with any patch tools (i.e. b4), shouldn't it? -michael
On 26/06/2022 21:56, Michael Walle wrote: > Am 2022-06-26 21:51, schrieb Krzysztof Kozlowski: >> On 26/06/2022 21:42, Michael Walle wrote: >>> 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> > > Thanks, I'll reorder the patches in the next version otherwise > there will likely be a conflict. Yes. > That should work with any patch > tools (i.e. b4), shouldn't it? You mean - re-ordering should work? Yes, no problem with that. Best regards, Krzysztof
On Sun, 26 Jun 2022 21:42:43 +0200 Michael Walle wrote: > 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. Whoa, are you using this code or just found the problem thru code inspection? NFC is notorious for having no known users.
Am 2022-06-28 07:03, schrieb Jakub Kicinski: > On Sun, 26 Jun 2022 21:42:43 +0200 Michael Walle wrote: >> 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. > > Whoa, are you using this code or just found the problem thru code > inspection? NFC is notorious for having no known users. Ha! Well, I *try* to use it with a PN7160. No luck so far, we'll see. At least the communication with the chip works now. I was also kinda tricked by the Supported status ;) -michael
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));
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> --- drivers/nfc/nxp-nci/i2c.c | 3 +++ 1 file changed, 3 insertions(+)