Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq

On Thu, Sep 07, 2017 at 02:44:11PM +0100, Mark Brown wrote:
 

quoted

On the other hand, the sys clock (baudclk in the driver) should be
configured whenever it's related to external clock outputs. When I
implemented this set_sysclk() for fsl_ssi.c, I used it to set this
sys clock (baudclk) by a machine driver, in order to set bit clock.
Then someone patched the driver by moving all the code to set_bclk()
to make machine drivers simpler. Now the set_sysclk() is remained
to give machine drivers a chance to override clock configurations
in the hw_params(). This could be used in TDM or some other special
cases (It could also have a purpose for backwards compatibility).

quoted

So here, we should set baudclk (BCLK generator).

No, that's just going to cause confusion - if all the other drivers are
using set_sysclk() to set an input clock rate to the IP rather than an
output clock but your driver does something else then sooner or later
someone will run into trouble with that.  

I admit I had that concern. Probably I should have deprecated this
set_sysclk(). I will try to patch it and hw_params() accordingly.