Re: [PATCH 1/2] NFC: nxp-nci: check return code of i2c_master_recv()

[Michael Walle]

Am 2022-06-26 21:49, schrieb Krzysztof Kozlowski:
> On 26/06/2022 21:42, Michael Walle wrote:
> > Check the return code of i2c_master_recv() for actual errors and
> > propagate it to the caller.
> >
> > Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI 
> > driver")
>
> The check was there, so I don't see here bug. The only thing missing 
> was
> a bit more detailed error message (without cast to %u) and propagating
> error code instead of EBADMSG, but these are not bugs. The commit msg
> should sound different and Fixes tag is not appropriate.

Well one could argue the nfc_err() is very misleading as it prints
an unreasonable large number. Will remove the Fixes tag and reword
the commit message.

> > Signed-off-by: Michael Walle <michael@xxxxxxxx>
> > ---
> >  drivers/nfc/nxp-nci/i2c.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
> > index 7e451c10985d..9c80d5a6d56b 100644
> > --- a/drivers/nfc/nxp-nci/i2c.c
> > +++ b/drivers/nfc/nxp-nci/i2c.c
> > @@ -163,7 +163,10 @@ static int nxp_nci_i2c_nci_read(struct 
> > nxp_nci_i2c_phy *phy,
> >  	skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
> >
> >  	r = i2c_master_recv(client, skb_put(*skb, header.plen), 
> > header.plen);
> > -	if (r != header.plen) {
> > +	if (r < 0) {
> > +		nfc_err(&client->dev, "I2C receive error %pe\n", ERR_PTR(r));
>
> Print just 'r'.

Personally, I prefer seeing the actual error string and this idiom is
also used in other drivers. But I wont insist, will change it.

> > +		goto nci_read_exit_free_skb;
> > +	} else if (r != header.plen) {
> >  		nfc_err(&client->dev,
> >  			"Invalid frame payload length: %u (expected %u)\n",
> >  			r, header.plen);
>
>
> Best regards,
> Krzysztof

-michael