Re: [PATCH V1 1/1] iio: Added Capella cm3232 ambient light sensor driver.

[Joe Perches <joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org>]

On Mon, 2015-01-05 at 16:20 +0200, Daniel Baluta wrote:
> On Mon, Jan 5, 2015 at 3:09 PM, Joe Perches <joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org> wrote:
> > On Mon, 2015-01-05 at 12:51 +0200, Daniel Baluta wrote:
> >> On Thu, Jan 1, 2015 at 2:10 AM, Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org> wrote:
> >> > CM3232 is an advanced ambient light sensor with I2C protocol interface.
> >> > The I2C slave address is internally hardwired as 0x10 (7-bit).  Writing
> >> > to configure register is byte mode, but reading ALS register requests to
> >> > use word mode for 16-bit resolution.
[]
> >> You could directly return i2c_smbus_write_byte_data(..).
> >
> > Sometimes it's better to return a specific value
> > for the error instead of depending on correctness
> > of all the indirect functions in the call chain.
> >
> > In this case, all the smbus_xfer functions must
> > return 0 on success.  Do they?
> 
> Yes.
> 
> http://lxr.free-electrons.com/source/drivers/i2c/i2c-core.c#L2845

This doesn't show that adapter->algo->smbus_xfer()
returns 0, you have to look at the code for that
indirectly called function. 

> Also, I guess kbuild test robot will complain about it, like here:
> 
> http://marc.info/?l=linux-kernel&m=141963536230419&w=2

Is the kbuild test robot now submitting patches for all
possible coccinelle simplifications?  I don't think so.