[alsa-devel] [PATCH 1/3] ASoC: DaVinci: i2s, reduce underruns by combining into 1 element

Troy Kisky troy.kisky at boundarydevices.com
Tue Sep 1 23:34:17 CEST 2009

Mark Brown wrote:
> On Tue, Sep 01, 2009 at 01:42:02PM -0700, Troy Kisky wrote:
>> Mark Brown wrote:
>>>> is using the same TC. But sram isn't on by default either. And probably shouldn't
>>>> be since the newer chips don't have an underrun problem.
>>> Hrm, that suggests that if it's enabled at all the default should depend
>>> on the chip in use?
>> That seems unnecessarily complex to me. As long as platform data can
>> specify what you need, you'll eventually get it right. If tracking of
>> an object is always wrong because of a channel swap, that is easier
>> to notice, and debug, and fix, then if the tracking is only occasionally
>> wrong. I'd much rather have a repeatable bug. And most codecs do allow
>> you to swap the left and right channels. So, for most people, the fix
>> will not be to disable channel combining.
> My thinking was that if the newer chips don't have the underrun issue at
> all then it seems like a bad move to enable the workaround for them
> since they're currently fine.  There should be no intermittent problems
> if the underrun issue isn't present.
True, there shouldn't be a problem. However, from a efficiency point of
view, it is still better to have the workaround. Fewer memory accesses
may free a little bandwidth for other uses.


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