Re: [PATCH v4 3/3] serial: 8250_of: manage bus clock in suspend/resume
From: Yixun Lan
Date: Fri Apr 11 2025 - 18:04:52 EST
hi Alex,
Glad to see first 2 patches already accepted
This version is better than v3, thanks
On 15:38 Fri 11 Apr , Alex Elder wrote:
> Save the bus clock pointer in the of_serial_info structure, and use
> that to disable the bus clock on suspend and re-enable it on resume.
>
> Signed-off-by: Alex Elder <elder@xxxxxxxxxxxx>
Reviewed-by: Yixun Lan <dlan@xxxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_of.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> index a90a5462aa72a..d178b6c54ea18 100644
> --- a/drivers/tty/serial/8250/8250_of.c
> +++ b/drivers/tty/serial/8250/8250_of.c
> @@ -24,6 +24,7 @@
>
> struct of_serial_info {
> struct clk *clk;
> + struct clk *bus_clk;
> struct reset_control *rst;
> int type;
> int line;
> @@ -138,6 +139,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
> goto err_pmruntime;
> }
>
> + info->bus_clk = bus_clk;
> port->uartclk = clk_get_rate(info->clk);
> }
> /* If current-speed was set, then try not to change it. */
> @@ -299,6 +301,7 @@ static int of_serial_suspend(struct device *dev)
> if (!uart_console(port) || console_suspend_enabled) {
> pm_runtime_put_sync(dev);
> clk_disable_unprepare(info->clk);
> + clk_disable_unprepare(info->bus_clk);
> }
> return 0;
> }
> @@ -311,6 +314,7 @@ static int of_serial_resume(struct device *dev)
>
> if (!uart_console(port) || console_suspend_enabled) {
> pm_runtime_get_sync(dev);
> + clk_prepare_enable(info->bus_clk);
> clk_prepare_enable(info->clk);
> }
>
> --
> 2.45.2
>
>
--
Yixun Lan (dlan)
Gentoo Linux Developer
GPG Key ID AABEFD55