On Mon, Jan 27, 2014 at 08:17:18AM +0100, Lars-Peter Clausen wrote:
On 01/24/2014 06:37 PM, Mark Brown wrote:
Thanks, that's about what I was going to write. The current theory is that setting the sysclk to zero is the equivalent of a dynamic SYSCLK flag - with the extensive use of charge pumps and so on in modern devices on the fly reclocking is normally difficult to do safely so the idea is that if the machine driver is in a position to reclock it should set the clock to zero.
It's a bit ugly though to set the clock to 0 in the startup callback of the machine driver and then set it to the actual sysclk in the hw_params callback.
If something is doing this I'd expect it to set the clock to zero when it is idled rather than during startup() - set_bias_level() is usually a good place to do this, or possibly a DAPM widget supplying the clocks in the device if the clocks are visible in DAPM. That's a bit nicer and doing it on startup runs into issues with things like bypass paths anyway.