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@riscstar.com>
---
 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

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@riscstar.com>
Reviewed-by: Yixun Lan <dlan@gentoo.org>

> ---
>  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

On Sat, Apr 12, 2025 at 1:04 AM Yixun Lan <dlan@gentoo.org> wrote:
>
> hi Alex,
>
> Glad to see first 2 patches already accepted
> This version is better than v3, thanks

Exactly! I'm not sure this series can be applied due to that. You need
to rebase on top of tty-next.

> 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@riscstar.com>
> Reviewed-by: Yixun Lan <dlan@gentoo.org>

Code wise this one is what I have expected, thanks!
Reviewed-by: Andy Shevchenko <andy@kernel.org>


-- 
With Best Regards,
Andy Shevchenko