Re: [PATCH] hwmon: (ina3221) Add voltage conversion time settings

From: Nicolin Chen
Date: Wed Apr 17 2019 - 15:48:26 EST

On Wed, Apr 17, 2019 at 11:39:49AM -0700, Nicolin Chen wrote:

> > Thinking about it ... does it even make sense to cache reg_config twice,
> > or would it be better to just update the local copy and use regmap_write()
> > to send it to the chip ?
> I remember the reason of adding the read-back was to prevent race
> condition. But now we have mutex protections for all sysfs nodes,
> maybe it's not necessary anymore. I will read the code carefully
> and see if it's safe to remove it -- will do in a separate patch.

I just recalled a second thought for the reason why I left them
there as it'd logically require a copy to restore upon failure
of regmap_write, that might not look so neat as the read-back:

old_config = reg_config;
reg_config &= mask;
reg_config |= val;
ret = regmap_write(reg_config);
if (ret) {
reg_config = old_config;
return ret;

Would you prefer this?