[PATCH] serial: 8250_mtk: Simplify clock sequencing and runtime PM

[Tony Lindgren]

* Chen-Yu Tsai <wenst at chromium.org> [230606 09:19]:
> The 8250_mtk driver's runtime PM support has some issues:
> 
> - The bus clock is enabled (through runtime PM callback) later than a
>   register write
> - runtime PM resume callback directly called in probe, but no
>   pm_runtime_set_active() call is present
> - UART PM function calls the callbacks directly, _and_ calls runtime
>   PM API
> - runtime PM callbacks try to do reference counting, adding yet another
>   count between runtime PM and clocks
> 
> This fragile setup worked in a way, but broke recently with runtime PM
> support added to the serial core. The system would hang when the UART
> console was probed and brought up.

Great, looks like a good for Linux next to me:

Reviewed-by: Tony Lindgren <tony at atomide.com>