[alsa-devel] [PATCH] ALSA: pcm: fix buffer_bytes max constrained by preallocated bytes issue

[Pierre-Louis Bossart]

>> So, do you suggest not doing preallocation(or calling it with 0 size) for all
>> driver with TYPE_SG? I am fine if this is the recommended method, I can try
>> this on SOF I2S platform to see if it can work as we required for very large
>> buffer size.

Keyon, for the rest of us to follow this patch, would you mind 
clarifying what drives the need for a 'very large buffer size', and what 
order of magnitude this very large size would be.

FWIW, we've measured consistently on different Windows/Linux platforms, 
maybe 10 years ago, that once you reach a buffer of 1s (384 kB) the 
benefits from increasing that buffer size further are marginal in terms 
of power consumption, and generate all kinds of issues with volume 
updates and deferred routing changes.

Thanks
-Pierre