On Thu, Sep 21, 2023 at 07:13:14PM +0800, Shengjiu Wang wrote:

Ratio modification on i.MX is to modify the configured ratio.
For example, the input rate is 44.1kHz,  output rate is 48kHz,
configured ratio = 441/480,   the ratio modification is to modify
the fractional part of (441/480) with small steps.  because the
input clock or output clock has drift in the real hardware.
The ratio modification is signed value, it is added to configured
ratio.

It does sound like something other vendors are likely to have to provide
a mechanism to compensate for clock inaccuracies.