Re: [PATCH v5 03/18] ACPI / table: Count matched and successfully parsed entries without specifying max entries

[Tomasz Nowicki]

On 24.11.2014 16:37, Rafael J. Wysocki wrote:
> On Monday, November 24, 2014 04:01:24 PM Tomasz Nowicki wrote:
> > On 24.11.2014 16:16, Rafael J. Wysocki wrote:
> > > On Monday, November 24, 2014 09:34:24 AM Tomasz Nowicki wrote:
> > > > On 24.11.2014 02:45, Rafael J. Wysocki wrote:
> > > > > On Friday, October 17, 2014 09:36:59 PM Hanjun Guo wrote:
> > > > > > From: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> > > > > >
> > > > > > It is very useful to traverse all available table entries without max
> > > > > > number of expected entries type. Current acpi_parse_entries()
> > > > > > implementation gives that feature but it does not count those entries,
> > > > > > it returns 0 instead, so fix it to count matched and successfully
> > > > > > entries and return it.
> > > > >
> > > > > Hmm.  I guess that the goal is for count to only be incremented when the
> > > > > condition is satisfied entirely, while without the patch it may be incremented
> > > > > even if that isn't the case.
> > > >
> > > > That would be our goal if patch would look like:
> > > > -		    && (!max_entries || count++ < max_entries))
> > > > +		    && (!max_entries && count++ < max_entries)) {
> > > > but then we can not walk through all available entries (with max_entries==0)
> > >
> > > No, that's not what I was trying to say. :-)
> > >
> > > > > I'm not sure how that is related to the above paragraph, however.
> > > >
> > > > Previous changelog is not clear, let me rewrite it:
> > > >
> > > > acpi_parse_entries() allows to traverse all available table entries (aka
> > > > subtables) by passing max_entries parameter equal to 0. But for that use
> > > > case acpi_parse_entries() does not inform caller how many entries were
> > > > matched and for how many entries handler was run against. That patch is
> > > > going to fix it.
> > >
> > > Do I understand correctly that count is only ever incremented by current code
> > > if max_entries is different from 0?
> >
> > Right. Currently "count" is incremented only if max_entries > 0.
>
> So can you say that in the changelog, please?
>
> Something like:
>
> "acpi_parse_entries() allows to traverse all available table entries (aka
>   subtables) by passing max_entries parameter equal to 0, but since its count
>   variable is only incremented if max_entries is not 0, the function always
>   returns 0 for max_entries equal to 0.  It would be more useful if it returned
>   the number of entries matched instead, so make it increment count in that
>   case too".

Sure, thanks.

Tomasz
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