[PATCH] serial: 8250_mtk: Simplify clock sequencing and runtime PM
Tony Lindgren
tony at atomide.com
Tue Jun 6 05:13:25 PDT 2023
* 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>
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