[PATCH] serial: ns16550: Try get serial clock rate from DT before CLK

[Quentin Schulz]

Hi Jonas,

On 8/4/24 5:09 PM, Jonas Karlman wrote:
> Initializing a clock driver to read a known static clock rate can take
> some time at U-Boot proper pre-reloc phase.
> 
> Change to first try and read clock rate from DT to speed up boot time,
> fall back to getting the clock rate from clock driver.
> 
> This help reduce boot time by around:
> - ~35ms on a Radxa ROCK Pi 4 (RK3399)
> - ~15ms on a Radxa ZERO 3W (RK3566)
> Time that is wasted getting a static rate known at compile time.
> 

I guess this also makes some board perform worse as well, the ones 
without a clock-frequency set?

The change seems sound to me, therefore
Reviewed-by: Quentin Schulz <quentin.schulz at cherry.de>

Thanks!
Quentin