Re: [PATCH v3 09/19] hwmon: (mr75203) add VM active channel support

[Farber, Eliav]

On 8/31/2022 2:48 PM, Andy Shevchenko wrote:
> On Tue, Aug 30, 2022 at 07:22:02PM +0000, Eliav Farber wrote:
> > Add active channel support per voltage monitor.
> > The number of active channels is read from the device-tree.
> > When absent in device-tree, all channels are assumed to be used.
> >
> > This shall be useful to expose sysfs only for inputs that are connected
> > to a voltage source.
> >
> > Setting number of active channels to 0, means that entire VM sensor is
> > not used.
>
> ...
>
> > +struct voltage_device {
> > +     u32 vm_map;     /* Map channel number to VM index */
> > +     u32 ch_map;     /* Map channel number to channel index */
> > +};
> > +
> > +struct voltage_channels {
> > +     u32 total;      /* Total number of channels in all VMs */
> > +     u8 max;         /* Maximum number of channels among all VMs */
> > +};
>
> Why not convert them to kernel doc?
Fixed in v4.


> > +     ret = device_property_read_u8_array(dev, 
> > "moortec,vm-active-channels",
> > +                                         vm_active_ch, vm_num);
> > +     if (ret) {
> > +             /*
> > +              * Incase vm-active-channels property is not defined,
> > +              * we assume each VM sensor has all of its channels
> > +              * active.
> > +              */
> > +             for (i = 0; i < vm_num; i++)
> > +                     vm_active_ch[i] = ch_num;
>
> NIH memset().

Fixed in v4.


> > +             pvt->vm_channels.max = ch_num;
> > +             pvt->vm_channels.total = ch_num * vm_num;
> > +     } else {
> > +             for (i = 0; i < vm_num; i++) {
> > +                     if (vm_active_ch[i] > ch_num) {
> > +                             dev_err(dev, "invalid active channels: 
> > %u\n",
> > +                                     vm_active_ch[i]);
> > +                             return -EINVAL;
> > +                     }
> > +
> > +                     pvt->vm_channels.total += vm_active_ch[i];
> > +
> > +                     if (vm_active_ch[i] > pvt->vm_channels.max)
> > +                             pvt->vm_channels.max = vm_active_ch[i];
> > +             }
> > +     }
>
> ...
>
> > +     k = 0;
> > +     for (i = 0; i < vm_num; i++)
> > +             for (j = 0; j < vm_active_ch[i]; j++) {
> > +                     pvt->vd[k].vm_map = vm_idx[i];
> > +                     pvt->vd[k].ch_map = j;
>
> > +                     k++;
>
> How is it different from moving this outside the inner loop as
>
>        k += vm_active_ch[i];
>
> ?

k is used inside the inner loop, so increasing it outside the inner loop
will result in a different incorrect setting of vm_map and ch_map.

> > +             }
>
> Missed outer {}.

Fixed in v4.


--
Regards, Eliav