[PATCH] wifi: wfx: Remove some dead code

[PATCH] wifi: wfx: Remove some dead code

[Christophe JAILLET]

wait_for_completion_timeout() can not return a <0 value.
So simplify the logic and remove dead code.

-ERESTARTSYS can not be returned by do_wait_for_common() for tasks with
TASK_UNINTERRUPTIBLE, which is the case for wait_for_completion_timeout()

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/net/wireless/silabs/wfx/main.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
index 6b9864e478ac..0b50f7058bbb 100644
--- a/drivers/net/wireless/silabs/wfx/main.c
+++ b/drivers/net/wireless/silabs/wfx/main.c
@@ -358,13 +358,9 @@ int wfx_probe(struct wfx_dev *wdev)
 
 	wfx_bh_poll_irq(wdev);
 	err = wait_for_completion_timeout(&wdev->firmware_ready, 1 * HZ);
-	if (err <= 0) {
-		if (err == 0) {
-			dev_err(wdev->dev, "timeout while waiting for startup indication\n");
-			err = -ETIMEDOUT;
-		} else if (err == -ERESTARTSYS) {
-			dev_info(wdev->dev, "probe interrupted by user\n");
-		}
+	if (err == 0) {
+		dev_err(wdev->dev, "timeout while waiting for startup indication\n");
+		err = -ETIMEDOUT;
 		goto bh_unregister;
 	}
 
-- 
2.34.1

Re: [PATCH] wifi: wfx: Remove some dead code

[Jérôme Pouiller]

Hello Christophe,

On Wednesday 15 February 2023 13:34:37 CET Christophe JAILLET wrote:
> 
> wait_for_completion_timeout() can not return a <0 value.
> So simplify the logic and remove dead code.
> 
> -ERESTARTSYS can not be returned by do_wait_for_common() for tasks with
> TASK_UNINTERRUPTIBLE, which is the case for wait_for_completion_timeout()
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/net/wireless/silabs/wfx/main.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
> index 6b9864e478ac..0b50f7058bbb 100644
> --- a/drivers/net/wireless/silabs/wfx/main.c
> +++ b/drivers/net/wireless/silabs/wfx/main.c
> @@ -358,13 +358,9 @@ int wfx_probe(struct wfx_dev *wdev)
> 
>         wfx_bh_poll_irq(wdev);
>         err = wait_for_completion_timeout(&wdev->firmware_ready, 1 * HZ);
> -       if (err <= 0) {
> -               if (err == 0) {
> -                       dev_err(wdev->dev, "timeout while waiting for startup indication\n");
> -                       err = -ETIMEDOUT;
> -               } else if (err == -ERESTARTSYS) {
> -                       dev_info(wdev->dev, "probe interrupted by user\n");

This code is ran during modprobe/insmod. We would like to allow the user
to interrupt (Ctrl+C) the probing if something is going wrong with the
device.

So, the real issue is wait_for_completion_interruptible_timeout() should
be used instead of wait_for_completion_timeout().

(By reading this code again, it also seems the test "if (err <= 0)" is
useless)


-- 
Jérôme Pouiller

Re: [PATCH] wifi: wfx: Remove some dead code

[Christophe JAILLET]

Le 15/02/2023 à 14:23, Jérôme Pouiller a écrit :
> Hello Christophe,
> 
> On Wednesday 15 February 2023 13:34:37 CET Christophe JAILLET wrote:
>>
>> wait_for_completion_timeout() can not return a <0 value.
>> So simplify the logic and remove dead code.
>>
>> -ERESTARTSYS can not be returned by do_wait_for_common() for tasks with
>> TASK_UNINTERRUPTIBLE, which is the case for wait_for_completion_timeout()
>>
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>>   drivers/net/wireless/silabs/wfx/main.c | 10 +++-------
>>   1 file changed, 3 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
>> index 6b9864e478ac..0b50f7058bbb 100644
>> --- a/drivers/net/wireless/silabs/wfx/main.c
>> +++ b/drivers/net/wireless/silabs/wfx/main.c
>> @@ -358,13 +358,9 @@ int wfx_probe(struct wfx_dev *wdev)
>>
>>          wfx_bh_poll_irq(wdev);
>>          err = wait_for_completion_timeout(&wdev->firmware_ready, 1 * HZ);
>> -       if (err <= 0) {
>> -               if (err == 0) {
>> -                       dev_err(wdev->dev, "timeout while waiting for startup indication\n");
>> -                       err = -ETIMEDOUT;
>> -               } else if (err == -ERESTARTSYS) {
>> -                       dev_info(wdev->dev, "probe interrupted by user\n");
> 
> This code is ran during modprobe/insmod. We would like to allow the user
> to interrupt (Ctrl+C) the probing if something is going wrong with the
> device.
> 
> So, the real issue is wait_for_completion_interruptible_timeout() should
> be used instead of wait_for_completion_timeout().

Hmmm, not that clear.

See commit 01088cd143a9.

Let me know if you prefer this patch as-is or if 01088cd143a9 should be 
reverted.

CJ

> 
> (By reading this code again, it also seems the test "if (err <= 0)" is
> useless)
> 
> 

Re: [PATCH] wifi: wfx: Remove some dead code

[Jérôme Pouiller]

On Friday 17 February 2023 20:51:24 CET Christophe JAILLET wrote:
> Le 15/02/2023 à 14:23, Jérôme Pouiller a écrit :
> > On Wednesday 15 February 2023 13:34:37 CET Christophe JAILLET wrote:
> >>
> >> wait_for_completion_timeout() can not return a <0 value.
> >> So simplify the logic and remove dead code.
> >>
> >> -ERESTARTSYS can not be returned by do_wait_for_common() for tasks with
> >> TASK_UNINTERRUPTIBLE, which is the case for wait_for_completion_timeout()
> >>
> >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> >> ---
> >>   drivers/net/wireless/silabs/wfx/main.c | 10 +++-------
> >>   1 file changed, 3 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
> >> index 6b9864e478ac..0b50f7058bbb 100644
> >> --- a/drivers/net/wireless/silabs/wfx/main.c
> >> +++ b/drivers/net/wireless/silabs/wfx/main.c
> >> @@ -358,13 +358,9 @@ int wfx_probe(struct wfx_dev *wdev)
> >>
> >>          wfx_bh_poll_irq(wdev);
> >>          err = wait_for_completion_timeout(&wdev->firmware_ready, 1 * HZ);
> >> -       if (err <= 0) {
> >> -               if (err == 0) {
> >> -                       dev_err(wdev->dev, "timeout while waiting for startup indication\n");
> >> -                       err = -ETIMEDOUT;
> >> -               } else if (err == -ERESTARTSYS) {
> >> -                       dev_info(wdev->dev, "probe interrupted by user\n");
> >
> > This code is ran during modprobe/insmod. We would like to allow the user
> > to interrupt (Ctrl+C) the probing if something is going wrong with the
> > device.
> >
> > So, the real issue is wait_for_completion_interruptible_timeout() should
> > be used instead of wait_for_completion_timeout().
> 
> Hmmm, not that clear.
> 
> See commit 01088cd143a9.
> 
> Let me know if you prefer this patch as-is or if 01088cd143a9 should be
> reverted.

Good catch. So this patch is correct.

Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>


-- 
Jérôme Pouiller

Re: [PATCH] wifi: wfx: Remove some dead code

[Kalle Valo]

Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> wait_for_completion_timeout() can not return a <0 value.
> So simplify the logic and remove dead code.
> 
> -ERESTARTSYS can not be returned by do_wait_for_common() for tasks with
> TASK_UNINTERRUPTIBLE, which is the case for wait_for_completion_timeout()
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>

Patch applied to wireless-next.git, thanks.

015bf4df8ea6 wifi: wfx: Remove some dead code

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/809c4a645c8d1306c0d256345515865c40ec731c.1676464422.git.christophe.jaillet@wanadoo.fr/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches