Re: [bug report] hwmon: ltc4282: add support for the LTC4282 chip

["Nuno Sá" <noname.nuno@gmail.com>]

On Wed, 2024-02-07 at 08:49 -0800, Guenter Roeck wrote:
> On 2/7/24 02:19, Nuno Sá wrote:
> > Hi Dan,
> > 
> > On Wed, 2024-02-07 at 12:51 +0300, Dan Carpenter wrote:
> > > Hello Nuno Sa,
> > > 
> > > The patch 848a5019ded5: "hwmon: ltc4282: add support for the LTC4282
> > > chip" from Jan 29, 2024 (linux-next), leads to the following Smatch
> > > static checker warning:
> > > 
> > > 	drivers/hwmon/ltc4282.c:732 ltc4282_write_voltage_byte_cached()
> > > 	warn: no lower bound on 'val' rl='s64min-4294967294'
> > > 
> > > drivers/hwmon/ltc4282.c
> > >      723 static int ltc4282_write_voltage_byte_cached(const struct
> > > ltc4282_state *st,
> > >      724                                              u32 reg, u32 fs,
> > > long
> > > val,
> > >      725                                              u32 *cache_raw)
> > >      726 {
> > >      727         u32 in;
> > >      728
> > >      729         if (val >= fs)
> > >      730                 in = U8_MAX;
> > >      731         else
> > > --> 732                 in = DIV_ROUND_CLOSEST(val * U8_MAX, fs);
> > 
> > Yeah, I guess we should likely clamp it between 0 and fs
> > 
> 
> 	val = clamp_val(val, 0, fs);
> 	in = DIV_ROUND_CLOSEST(val * U8_MAX, fs);
> 
> maybe.
> 
> Should I fix that inline or do you want to send a follow-up patch ?
> 
> Guenter
> 
> 

Whatever makes your life easier... I can send a patch if that is your
preference.

- Nuno Sá