On Tue, May 19, 2020 at 08:50:22AM -0700, Reinette Chatre wrote:
> On 5/19/2020 1:28 AM, Andy Shevchenko wrote:
> > On Tue, May 19, 2020 at 2:50 AM Reinette Chatre
> > <reinette.cha...@intel.com> wrote:
...
> >> + ret = sysfs_match_string(rdt_mode_str, buf);
> >> + if (ret < 0) {
> >> + rdt_last_cmd_puts("Unknown or unsupported mode\n");
> >> + ret = -EINVAL;
> >> + goto out;
> >> + }
>
> From your previous email ...
>
> >> + ret = sysfs_match_string(rdt_mode_str, buf);
> >> + if (ret < 0) {
> >> + rdt_last_cmd_puts("Unknown or unsupported mode\n");
> >
> >> + ret = -EINVAL;
> >
> > This is redundant.
>
> I understand that shadowing an error code is generally of concern. In
> this case the error code is set to -EINVAL to ensure that it is the same
> error code that was returned to user space originally and will continue
> to be so no matter what changes may come to sysfs_match_string().
It returns -EINVAL and if that will be ever changed this driver would be one of
hundreds who suffers.
...
> > Can't we unify latter with a former like ...
> This would have been ideal if done from the start but currently "0" is
> returned if the current mode is pseudo-locked and user attempts to
> change the mode to pseudo-locked. Thus, to maintain the current user
> interface the check if user wants to set pseudo-locked mode is moved
> after the check if new mode is same as existing mode and thus not
> unified because that will result in an error returned always when user
> requests pseudo-locked mode.
Ah, I see now.
But we can then drop the check from sysfs_match_string() returned value, like
user_m = sysfs_match_string();
if (...) {
...
} else { // w/o even checking for the PSEUDO_LOCKED
...
goto out;
}
Can we?
--
With Best Regards,
Andy Shevchenko
