From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH] i2c/mips: Fix error return codes from Sibyte i2c bus driver Date: Tue, 22 Jun 2010 04:54:17 -0700 Message-ID: <20100622115417.GA14418@ericsson.com> References: <1277056673-4305-1-git-send-email-guenter.roeck@ericsson.com> <20100621190252.2adc6bd8@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20100621190252.2adc6bd8-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: "ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org" , "hsweeten-3FF4nKcrg1dE2c76skzGb0EOCMrvLtNR@public.gmane.org" , "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-i2c@vger.kernel.org On Mon, Jun 21, 2010 at 01:02:52PM -0400, Jean Delvare wrote: > Hi Guenter, > > On Sun, 20 Jun 2010 10:57:53 -0700, Guenter Roeck wrote: > > Sibyte i2c bus driver returns non-descriptive error values. > > Update to return error values as defined in Documentation/i2c/fault-codes. > > > > Signed-off-by: Guenter Roeck > > --- > > drivers/i2c/busses/i2c-sibyte.c | 4 ++-- > > 1 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-sibyte.c b/drivers/i2c/busses/i2c-sibyte.c > > index 3d76a18..329cbee 100644 > > --- a/drivers/i2c/busses/i2c-sibyte.c > > +++ b/drivers/i2c/busses/i2c-sibyte.c > > @@ -94,7 +94,7 @@ static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, > > } > > break; > > default: > > - return -1; /* XXXKW better error code? */ > > + return -EOPNOTSUPP; > > } > > > > while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) > > @@ -104,7 +104,7 @@ static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, > > if (error & M_SMB_ERROR) { > > /* Clear error bit by writing a 1 */ > > csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS)); > > - return -1; /* XXXKW better error code? */ > > + return -ENXIO; > > } > > > > if (data_bytes == 1) > > Definitely an improvement. However, returning -ENXIO on all errors > seems wrong. This error value should only be returned on missing ack > from the slave on address byte. Isn't it possible to distinguish > between different error kinds? M_SMB_ERROR_TYPE seems promising, but > one would need to look up the datasheet (which I don't have) to > discover its meaning. > Makes sense. I'll dig up a copy of the datasheet and see if I can improve it. Guenter