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* [PATCH] clk: handle NULL args in clk_set_parent()
@ 2022-05-11 10:09 Bastian Krause
  2022-05-11 10:27 ` Ahmad Fatoum
  2022-05-12  7:03 ` Sascha Hauer
  0 siblings, 2 replies; 5+ messages in thread
From: Bastian Krause @ 2022-05-11 10:09 UTC (permalink / raw)
  To: barebox; +Cc: Ahmad Fatoum, Bastian Krause

NULL struct clk pointers should be treated just as the Linux kernel clk
driver does [1]. The reasoning should also apply to the parent clk
argument.

A NULL struct clk pointer can happen for example on the Freescale i.MX6
SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled,
leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and
IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the
board hangs while setting those assigned clock configurations since [3].

[1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully")
[2] dts/src/arm/imx6qdl-sabresd.dtsi
[3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider")

Signed-off-by: Bastian Krause <bst@pengutronix.de>
---
 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 8e317b4b05..efb5d4ad4a 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -230,7 +230,10 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
 {
 	struct clk_hw *hw;
 	int i, ret;
-	struct clk *curparent = clk_get_parent(clk);
+	struct clk *curparent;
+
+	if (!clk || !newparent)
+		return 0;
 
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
@@ -254,6 +257,8 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
 	if (i == clk->num_parents)
 		return -EINVAL;
 
+	curparent = clk_get_parent(clk);
+
 	if (clk->enable_count)
 		clk_enable(newparent);
 
-- 
2.30.2


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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] clk: handle NULL args in clk_set_parent()
  2022-05-11 10:09 [PATCH] clk: handle NULL args in clk_set_parent() Bastian Krause
@ 2022-05-11 10:27 ` Ahmad Fatoum
  2022-05-12  7:03 ` Sascha Hauer
  1 sibling, 0 replies; 5+ messages in thread
From: Ahmad Fatoum @ 2022-05-11 10:27 UTC (permalink / raw)
  To: Bastian Krause, barebox

Hello Bastian,

On 11.05.22 12:09, Bastian Krause wrote:
> NULL struct clk pointers should be treated just as the Linux kernel clk
> driver does [1]. The reasoning should also apply to the parent clk
> argument.
> 
> A NULL struct clk pointer can happen for example on the Freescale i.MX6
> SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled,
> leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and
> IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the
> board hangs while setting those assigned clock configurations since [3].
> 
> [1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully")
> [2] dts/src/arm/imx6qdl-sabresd.dtsi
> [3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider")

Thanks for your patch.

> 
> Signed-off-by: Bastian Krause <bst@pengutronix.de>
> ---
>  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 8e317b4b05..efb5d4ad4a 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -230,7 +230,10 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
>  {
>  	struct clk_hw *hw;
>  	int i, ret;
> -	struct clk *curparent = clk_get_parent(clk);

Linux clk_get_parent returns NULL if clk is NULL.
Can you teach barebox to do the same?

Linux clk_set_parent accepts a NULL parent to add a clock
to the orphan list. We don't seem to maintain an orphan
list in barebox, so early exist with return value zero
seems okay.

> +	struct clk *curparent;
> +
> +	if (!clk || !newparent)
> +		return 0;
>  
>  	if (IS_ERR(clk))
>  		return PTR_ERR(clk);
> @@ -254,6 +257,8 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
>  	if (i == clk->num_parents)
>  		return -EINVAL;
>  
> +	curparent = clk_get_parent(clk);
> +

With early-exiting clk_get_parent, you won't need to shift this code around.

Cheers,
Ahmad

>  	if (clk->enable_count)
>  		clk_enable(newparent);
>  


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] clk: handle NULL args in clk_set_parent()
  2022-05-11 10:09 [PATCH] clk: handle NULL args in clk_set_parent() Bastian Krause
  2022-05-11 10:27 ` Ahmad Fatoum
@ 2022-05-12  7:03 ` Sascha Hauer
  2022-05-12  8:54   ` Bastian Krause
  1 sibling, 1 reply; 5+ messages in thread
From: Sascha Hauer @ 2022-05-12  7:03 UTC (permalink / raw)
  To: Bastian Krause; +Cc: barebox, Ahmad Fatoum

On Wed, May 11, 2022 at 12:09:11PM +0200, Bastian Krause wrote:
> NULL struct clk pointers should be treated just as the Linux kernel clk
> driver does [1]. The reasoning should also apply to the parent clk
> argument.
> 
> A NULL struct clk pointer can happen for example on the Freescale i.MX6
> SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled,
> leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and
> IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the
> board hangs while setting those assigned clock configurations since [3].
> 
> [1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully")
> [2] dts/src/arm/imx6qdl-sabresd.dtsi
> [3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider")
> 
> Signed-off-by: Bastian Krause <bst@pengutronix.de>
> ---
>  drivers/clk/clk.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 8e317b4b05..efb5d4ad4a 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -230,7 +230,10 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
>  {
>  	struct clk_hw *hw;
>  	int i, ret;
> -	struct clk *curparent = clk_get_parent(clk);
> +	struct clk *curparent;
> +
> +	if (!clk || !newparent)
> +		return 0;
>  
>  	if (IS_ERR(clk))
>  		return PTR_ERR(clk);
> @@ -254,6 +257,8 @@ int clk_set_parent(struct clk *clk, struct clk *newparent)
>  	if (i == clk->num_parents)
>  		return -EINVAL;
>  
> +	curparent = clk_get_parent(clk);
> +
>  	if (clk->enable_count)
>  		clk_enable(newparent);
>  
> -- 
> 2.30.2
> 
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] clk: handle NULL args in clk_set_parent()
  2022-05-12  7:03 ` Sascha Hauer
@ 2022-05-12  8:54   ` Bastian Krause
  2022-05-12  9:19     ` Sascha Hauer
  0 siblings, 1 reply; 5+ messages in thread
From: Bastian Krause @ 2022-05-12  8:54 UTC (permalink / raw)
  To: Sascha Hauer; +Cc: barebox, Ahmad Fatoum

Hi Sascha,

On 5/12/22 09:03, Sascha Hauer wrote:
> On Wed, May 11, 2022 at 12:09:11PM +0200, Bastian Krause wrote:
>> NULL struct clk pointers should be treated just as the Linux kernel clk
>> driver does [1]. The reasoning should also apply to the parent clk
>> argument.
>>
>> A NULL struct clk pointer can happen for example on the Freescale i.MX6
>> SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled,
>> leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and
>> IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the
>> board hangs while setting those assigned clock configurations since [3].
>>
>> [1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully")
>> [2] dts/src/arm/imx6qdl-sabresd.dtsi
>> [3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider")
>>
>> Signed-off-by: Bastian Krause <bst@pengutronix.de>
>> ---
>>   drivers/clk/clk.c | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> Applied, thanks

Did you see the v2 of this patch?

Regards,
Bastian

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] clk: handle NULL args in clk_set_parent()
  2022-05-12  8:54   ` Bastian Krause
@ 2022-05-12  9:19     ` Sascha Hauer
  0 siblings, 0 replies; 5+ messages in thread
From: Sascha Hauer @ 2022-05-12  9:19 UTC (permalink / raw)
  To: Bastian Krause; +Cc: barebox, Ahmad Fatoum

On Thu, May 12, 2022 at 10:54:37AM +0200, Bastian Krause wrote:
> Hi Sascha,
> 
> On 5/12/22 09:03, Sascha Hauer wrote:
> > On Wed, May 11, 2022 at 12:09:11PM +0200, Bastian Krause wrote:
> > > NULL struct clk pointers should be treated just as the Linux kernel clk
> > > driver does [1]. The reasoning should also apply to the parent clk
> > > argument.
> > > 
> > > A NULL struct clk pointer can happen for example on the Freescale i.MX6
> > > SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled,
> > > leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and
> > > IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the
> > > board hangs while setting those assigned clock configurations since [3].
> > > 
> > > [1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully")
> > > [2] dts/src/arm/imx6qdl-sabresd.dtsi
> > > [3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider")
> > > 
> > > Signed-off-by: Bastian Krause <bst@pengutronix.de>
> > > ---
> > >   drivers/clk/clk.c | 7 ++++++-
> > >   1 file changed, 6 insertions(+), 1 deletion(-)
> > 
> > Applied, thanks
> 
> Did you see the v2 of this patch?

Yes, but still I accidently applied v1 and then fixed it up to v2 :/

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2022-05-12  9:21 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-11 10:09 [PATCH] clk: handle NULL args in clk_set_parent() Bastian Krause
2022-05-11 10:27 ` Ahmad Fatoum
2022-05-12  7:03 ` Sascha Hauer
2022-05-12  8:54   ` Bastian Krause
2022-05-12  9:19     ` Sascha Hauer

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