[PATCH] ASoC: samsung: i2s: Check before clk_unregister() not needed

[PATCH] ASoC: samsung: i2s: Check before clk_unregister() not needed

[Yihao Han]

clk_unregister() already checks the clk ptr using
!clk || WARN_ON_ONCE(IS_ERR(clk)) so there is no need to check it
again before calling it.

Signed-off-by: Yihao Han <hanyihao@vivo.com>
---
 sound/soc/samsung/i2s.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index 70c827162be4..84e21f7fc179 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -1247,8 +1247,7 @@ static void i2s_unregister_clocks(struct samsung_i2s_priv *priv)
 	int i;
 
 	for (i = 0; i < priv->clk_data.clk_num; i++) {
-		if (!IS_ERR(priv->clk_table[i]))
-			clk_unregister(priv->clk_table[i]);
+		clk_unregister(priv->clk_table[i]);
 	}
 }
 
-- 
2.17.1

Re: [PATCH] ASoC: samsung: i2s: Check before clk_unregister() not needed

[Krzysztof Kozlowski]

On 27/05/2022 08:54, Yihao Han wrote:
> clk_unregister() already checks the clk ptr using
> !clk || WARN_ON_ONCE(IS_ERR(clk)) so there is no need to check it
> again before calling it.
> 

No, this explanation does not make sense. clk_unregister() warns and
this code is not equivalent.



Best regards,
Krzysztof

Re: [PATCH] ASoC: samsung: i2s: Check before clk_unregister() not needed

[Christophe JAILLET]

Le 29/05/2022 à 10:06, Krzysztof Kozlowski a écrit :
> On 27/05/2022 08:54, Yihao Han wrote:
>> clk_unregister() already checks the clk ptr using
>> !clk || WARN_ON_ONCE(IS_ERR(clk)) so there is no need to check it
>> again before calling it.
>>
> 
> No, this explanation does not make sense. clk_unregister() warns and
> this code is not equivalent.
> 
> 
> 
> Best regards,
> Krzysztof
> 

Hi,

Moreover, as pointed out by greg in [1] on some plateform the assertion 
in the commit description is wrong. His message is about clk_disable() 
but, IIUC, it makes sense for clk_unregister() as well. See [2] on the 
sh plateform.

CJ

[1]: https://lore.kernel.org/all/YqMIUOTU%2Fk5XpW3I@kroah.com/
[2]: 
https://elixir.bootlin.com/linux/v5.18.3/source/drivers/sh/clk/core.c#L452

Re: [PATCH] ASoC: samsung: i2s: Check before clk_unregister() not needed

[Krzysztof Kozlowski]

On 10/06/2022 18:15, Christophe JAILLET wrote:
> Le 29/05/2022 à 10:06, Krzysztof Kozlowski a écrit :
>> On 27/05/2022 08:54, Yihao Han wrote:
>>> clk_unregister() already checks the clk ptr using
>>> !clk || WARN_ON_ONCE(IS_ERR(clk)) so there is no need to check it
>>> again before calling it.
>>>
>>
>> No, this explanation does not make sense. clk_unregister() warns and
>> this code is not equivalent.
>>
>>
>>
>> Best regards,
>> Krzysztof
>>
> 
> Hi,
> 
> Moreover, as pointed out by greg in [1] on some plateform the assertion 
> in the commit description is wrong. His message is about clk_disable() 
> but, IIUC, it makes sense for clk_unregister() as well. See [2] on the 
> sh plateform.
> 

Yes, this is true as well, although does not have the practical impact
on this driver as it uses platforms with common clock framework.


Best regards,
Krzysztof