linux-kernel - Re: [PATCH v2] clk: Warn about critical clks that fail to enable

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Date:   Thu, 02 Jan 2020 13:47:53 +0100
From:   Jerome Brunet <jbrunet@...libre.com>
To:     Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH v2] clk: Warn about critical clks that fail to enable


On Thu 02 Jan 2020 at 01:55, Stephen Boyd <sboyd@...nel.org> wrote:

> If we don't warn here users of the CLK_IS_CRITICAL flag may not know
> that their clk isn't actually enabled because it silently fails to
> enable. Let's print a warning in that case so developers find these
> problems faster.

Thanks Stephen !
Reviewed-by: Jerome Brunet <jbrunet@...libre.com>

>
> Suggested-by: Jerome Brunet <jbrunet@...libre.com>
> Cc: Guenter Roeck <linux@...ck-us.net>
> Signed-off-by: Stephen Boyd <sboyd@...nel.org>
> ---
>
> Changes from v1:
>  * Switched to pr_warn and indicated clk name
>
>  drivers/clk/clk.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 772258de2d1f..b03c2be4014b 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3427,13 +3427,18 @@ static int __clk_core_init(struct clk_core *core)
>  		unsigned long flags;
>  
>  		ret = clk_core_prepare(core);
> -		if (ret)
> +		if (ret) {
> +			pr_warn("%s: critical clk '%s' failed to prepare\n",
> +			       __func__, core->name);
>  			goto out;
> +		}
>  
>  		flags = clk_enable_lock();
>  		ret = clk_core_enable(core);
>  		clk_enable_unlock(flags);
>  		if (ret) {
> +			pr_warn("%s: critical clk '%s' failed to enable\n",
> +			       __func__, core->name);
>  			clk_core_unprepare(core);
>  			goto out;
>  		}
>
> base-commit: 12ead77432f2ce32dea797742316d15c5800cb32