Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] PM / OPP: predictable fail results for opp_find* functions | Date | Fri, 19 Oct 2012 01:18:34 +0200 |
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On Wednesday 17 of October 2012 15:14:22 Kevin Hilman wrote: > Nishanth Menon <nm@ti.com> writes: > > > Currently the opp_find* functions return -ENODEV when: > > a) it cant find a device (e.g. request for an OPP search on device > > which was not registered) > > b) When it cant find a match for the search strategy used > > > > This makes life a little in-efficient for users such as devfreq > > to make reasonable judgement before switching search strategies. > > > > So, standardize the return results as following: > > -EINVAL for bad pointer parameters > > -ENODEV when device cannot be found > > -ERANGE when search fails > > > > This has the following benefit for devfreq implementation: > > > > Current code: > > opp = opp_find_freq_floor(dev, freq); > > /* Following search triggers even for un-registered device */ > > if (opp == ERR_PTR(-ENODEV)) > > opp = opp_find_freq_ceil(dev, freq); > > > > Vs (after this change): > > opp = opp_find_freq_floor(dev, freq); > > /* Will only be triggered if search logic fails: intended usage */ > > if (opp == ERR_PTR(-ERANGE)) > > opp = opp_find_freq_ceil(dev, freq); > > I think the idea is fine but would prefer to see the benefits summarized > in words, rather than code. > > Also, the changelog should describe that the patch not only changes the > meaning of return values, but also converts devfreq to use the new > values. > > Otherwise, implementation looks fine. > > Reviewed-by: Kevin Hilman <khilman@ti.com>
Can you please update the patch as requested by Kevin?
Thanks, Rafael
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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