2019年11月12日(火) 1:53 Christoph Hellwig <hch@xxxxxx>:
>
> On Sun, Nov 10, 2019 at 11:17:46PM +0900, Akinobu Mita wrote:
> > +static int nvme_get_temp_thresh(struct nvme_ctrl *ctrl, int sensor, bool under,
> > + long *temp)
> > +{
> > + unsigned int threshold = sensor << NVME_TEMP_THRESH_SELECT_SHIFT;
> > + int status;
> > + int ret;
> > +
> > + if (under)
> > + threshold |= NVME_TEMP_THRESH_TYPE_UNDER;
> > +
> > + ret = nvme_get_features(ctrl, NVME_FEAT_TEMP_THRESH, threshold, NULL, 0,
> > + &status);
> > + if (!ret)
> > + *temp = ((status & NVME_TEMP_THRESH_MASK) - 273) * 1000;
> > +
> > + return ret <= 0 ? ret : -EIO;
>
> This looks a little obsfucated. aI'd prefer something like:
>
> if (ret > 0)
> return -EIO;
> if (ret < 0)
> return ret;
> *temp = ((status & NVME_TEMP_THRESH_MASK) - 273) * 1000;
> return 0;
Sounds good.
> > + return ret <= 0 ? ret : -EIO;
>
> Similarly here, something like:
>
> if (ret > 0)
> return -EIO;
> return ret;
OK.
> > + err = nvme_get_temp_thresh(data->ctrl, channel, false, val);
> > + if (err)
> > + *val = (data->ctrl->wctemp - 273) * 1000;
>
> Can we have a helper for this (x - 273) * 1000 conversion? It is
> repeated quite a bit over the code in this file.
OK. I'll add two macros.
#define MILLICELSIUS_TO_KELVIN(t) ((t) / 1000 + 273)
#define KELVIN_TO_MILLICELSIUS(t) (((t) - 273) * 1000)
