[PATCH] clk: Warn about critical clks that fail to enable

[PATCH] clk: Warn about critical clks that fail to enable

[Stephen Boyd]

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 drop a big WARN_ON in that case so developers find these
problems faster.

Suggested-by: Jerome Brunet <jbrunet@baylibre.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
---

I suspect that this may start warning for other users. Let's see
and revert in case it doesn't work.

 drivers/clk/clk.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 772258de2d1f..6a9a66dfdeaa 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3427,13 +3427,13 @@ static int __clk_core_init(struct clk_core *core)
 		unsigned long flags;
 
 		ret = clk_core_prepare(core);
-		if (ret)
+		if (WARN_ON(ret))
 			goto out;
 
 		flags = clk_enable_lock();
 		ret = clk_core_enable(core);
 		clk_enable_unlock(flags);
-		if (ret) {
+		if (WARN_ON(ret)) {
 			clk_core_unprepare(core);
 			goto out;
 		}

base-commit: 12ead77432f2ce32dea797742316d15c5800cb32
-- 
Sent by a computer, using git, on the internet

Re: [PATCH] clk: Warn about critical clks that fail to enable

[Markus Elfring]

> 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 drop a big WARN_ON in that case so developers find these
> problems faster.

Would you like to avoid an extra warning for failures with non-critical clocks?


> I suspect that this may start warning for other users.

Will this software development concern trigger any further collateral evolution?

Regards,
Markus

Re: [PATCH] clk: Warn about critical clks that fail to enable

[Stephen Boyd]

Quoting Stephen Boyd (2019-12-26 14:13:54)
> 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 drop a big WARN_ON in that case so developers find these
> problems faster.
> 
> Suggested-by: Jerome Brunet <jbrunet@baylibre.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> ---
> 
> I suspect that this may start warning for other users. Let's see
> and revert in case it doesn't work.
> 
>  drivers/clk/clk.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 772258de2d1f..6a9a66dfdeaa 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3427,13 +3427,13 @@ static int __clk_core_init(struct clk_core *core)
>                 unsigned long flags;
>  
>                 ret = clk_core_prepare(core);
> -               if (ret)
> +               if (WARN_ON(ret))

We should probably just print the clk name that failed to be critically
enabled with a pr_warn(). The traceback pointing to this location will
be really hard to understand otherwise.

>                         goto out;
>  
>                 flags = clk_enable_lock();
>                 ret = clk_core_enable(core);
>                 clk_enable_unlock(flags);
> -               if (ret) {
> +               if (WARN_ON(ret)) {
>                         clk_core_unprepare(core);
>                         goto out;
>                 }
> 
> base-commit: 12ead77432f2ce32dea797742316d15c5800cb32
> -- 
> Sent by a computer, using git, on the internet
> 

Re: [PATCH] clk: Warn about critical clks that fail to enable

[Guenter Roeck]

On Mon, Dec 30, 2019 at 09:55:17AM -0800, Stephen Boyd wrote:
> Quoting Stephen Boyd (2019-12-26 14:13:54)
> > 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 drop a big WARN_ON in that case so developers find these
> > problems faster.
> > 
> > Suggested-by: Jerome Brunet <jbrunet@baylibre.com>
> > Cc: Guenter Roeck <linux@roeck-us.net>
> > Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> > ---
> > 
> > I suspect that this may start warning for other users. Let's see
> > and revert in case it doesn't work.
> > 
> >  drivers/clk/clk.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> > index 772258de2d1f..6a9a66dfdeaa 100644
> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -3427,13 +3427,13 @@ static int __clk_core_init(struct clk_core *core)
> >                 unsigned long flags;
> >  
> >                 ret = clk_core_prepare(core);
> > -               if (ret)
> > +               if (WARN_ON(ret))
> 
> We should probably just print the clk name that failed to be critically
> enabled with a pr_warn(). The traceback pointing to this location will
> be really hard to understand otherwise.
> 
Agreed.

Guenter

> >                         goto out;
> >  
> >                 flags = clk_enable_lock();
> >                 ret = clk_core_enable(core);
> >                 clk_enable_unlock(flags);
> > -               if (ret) {
> > +               if (WARN_ON(ret)) {
> >                         clk_core_unprepare(core);
> >                         goto out;
> >                 }
> > 
> > base-commit: 12ead77432f2ce32dea797742316d15c5800cb32
> > -- 
> > Sent by a computer, using git, on the internet
> >