Re: [PATCH 1/3] ALSA: compress_core: Update calc_avail to use cumulative values

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 04/03/2013 07:13 AM, Charles Keepax wrote:
> The app_pointer is managed locally by the compress core for memory
> mapped DSPs but for DSPs that are not memory mapped this would have to
> be manually updated from within the DSP driver itself, which is hardly
> very idiomatic.
>
> This patch switches to using the cumulative values to calculate the
> available buffer space because these are already gracefully passed out
> of the DSP driver to the compress core and otherwise should be
> functionally equivalent.

This isn't very elegant. In your implementation you bypass app_ptr and 
hw_ptr to use cumulative values, for 'memory-mapped' DSPs we use app_ptr 
and hw_ptr everywhere else. This patch seems to make things more 
confused when they could be simpler without all these redundant fields? 
I am probably partly responsible for the introduction of these 
cumulative values, now I think the time has come to simplify things.
-Pierre