Re: [PATCH] leds: ti-lmu-common: Fix coccinelle issue in TI LMU

[Dan Murphy]

Jacek

On 8/26/19 2:34 PM, Jacek Anaszewski wrote:
> Dan,
>
> On 8/26/19 4:53 PM, Dan Murphy wrote:
> > Jacek
> >
> > On 8/24/19 10:18 AM, Jacek Anaszewski wrote:
> > > Hi Dan,
> > >
> > > Thank you for the patch.
> > >
> > > On 8/23/19 9:55 PM, Dan Murphy wrote:
> > > > Fix the coccinelle issues found in the TI LMU common code
> > > >
> > > > drivers/leds/leds-ti-lmu-common.c:97:20-29: WARNING: Unsigned
> > > > expression compared with zero: ramp_down < 0
> > > > drivers/leds/leds-ti-lmu-common.c:97:5-12: WARNING: Unsigned
> > > > expression compared with zero: ramp_up < 0
> > > Wouldn't it make more sense to remove those pointless checks?
> > > Clearly a correct index of an array cannot be negative.
> > > Looking at the code I would make more int -> unsigned int conversions:
> > >
> > > - ramp_table should be unsigned int
> > > - ti_lmu_common_convert_ramp_to_index should return unsigned int
> > Yeah I was going to just remove the code but when I was writing the
> > original code my intent was
> >
> > to extend the ramp call to allow other TI LMU driver to pass in the
> > device specific ramp table.
> >
> > But since I don't currently have any devices on my plate that require
> > that I can just remove the code as well
> You don't need to remove, just do the conversions I proposed.
> Unless it introduces some other problems I am currently not aware of.
Well just converting those two would/did not fix the issue.

But actually there is only 1 possibility that could happen if the 
convert function returns -EINVAL

So the check should be

if (ramp_up == -EINVAL || ramp_down == -EINVAL)

Because ramp_up/down should never be less then zero otherwise.

Dan