Hello,
On Mon, Sep 19, 2022 at 03:39:15PM -0700, Olof Johansson wrote:
> When the PWM driver was changed to disable clocks if no PWMs are enabled,
> it ended up also disabling the shared parent with the UART, since the
> UART doesn't do any clock enablement on its own.
>
> To avoid these surprises, add clk_prepare_enable/clk_disable_unprepare
> calls.
>
> Fixes: ace41d7564e655 ("pwm: sifive: Ensure the clk is enabled exactly once per running PWM")
> Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> Cc: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
> ---
> drivers/tty/serial/sifive.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
> index 5c3a07546a58..751f98068806 100644
> --- a/drivers/tty/serial/sifive.c
> +++ b/drivers/tty/serial/sifive.c
> @@ -950,23 +950,28 @@ static int sifive_serial_probe(struct platform_device *pdev)
> dev_err(&pdev->dev, "unable to find controller clock\n");
> return PTR_ERR(clk);
> }
> + clk_prepare_enable(clk);
The return code of clk_prepare_enable() must be checked. Also there is a
simpler patch to fix that problem. I didn't test but I expect just doing
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
index 5c3a07546a58..4b1d4fe8458e 100644
--- a/drivers/tty/serial/sifive.c
+++ b/drivers/tty/serial/sifive.c
@@ -945,7 +945,7 @@ static int sifive_serial_probe(struct platform_device *pdev)
return PTR_ERR(base);
}
- clk = devm_clk_get(&pdev->dev, NULL);
+ clk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "unable to find controller clock\n");
return PTR_ERR(clk);
would be enough and also cares for disabling the clock on remove.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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