2022-09-19 09:01:12

by Li Zhong

Subject: [PATCH v1] drivers/tty/serial/8250: check the return value of clk_prepare_enable()

Check the return value of clk_prepare_enable() which could fail when
cannot enable the clock.

Signed-off-by: Li Zhong <[email protected]>
---
drivers/tty/serial/8250/8250_of.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 1b461fba15a3..23e9b9e8c940 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -298,7 +298,8 @@ static int of_serial_resume(struct device *dev)

if (!uart_console(port) || console_suspend_enabled) {
pm_runtime_get_sync(dev);
- clk_prepare_enable(info->clk);
+ if (clk_prepare_enable(info->clk) < 0)
+ dev_warn(dev, "can't enable clk.\n");
}

serial8250_resume_port(info->line);
--
2.25.1

2022-09-19 09:49:37

by Greg KH

Subject: Re: [PATCH v1] drivers/tty/serial/8250: check the return value of clk_prepare_enable()

On Mon, Sep 19, 2022 at 01:54:55AM -0700, Li Zhong wrote:
> Check the return value of clk_prepare_enable() which could fail when
> cannot enable the clock.
>
> Signed-off-by: Li Zhong <[email protected]>
> ---
> drivers/tty/serial/8250/8250_of.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> index 1b461fba15a3..23e9b9e8c940 100644
> --- a/drivers/tty/serial/8250/8250_of.c
> +++ b/drivers/tty/serial/8250/8250_of.c
> @@ -298,7 +298,8 @@ static int of_serial_resume(struct device *dev)
>
> if (!uart_console(port) || console_suspend_enabled) {
> pm_runtime_get_sync(dev);
> - clk_prepare_enable(info->clk);
> + if (clk_prepare_enable(info->clk) < 0)
> + dev_warn(dev, "can't enable clk.\n");

Again, you check but do nothing with the error :(