2023-02-15 12:35:10

by Christophe JAILLET

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

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 <[email protected]>
---
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

2023-02-15 13:24:17

by Jérôme Pouiller

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

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 <[email protected]>
> ---
> 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)


--
J?r?me Pouiller

2023-02-17 19:51:34

by Christophe JAILLET

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

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 <[email protected]>
>> ---
>> 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)
>
>

2023-02-21 17:03:18

by Jérôme Pouiller

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

On Friday 17 February 2023 20:51:24 CET Christophe JAILLET wrote:
> Le 15/02/2023 ? 14:23, J?r?me Pouiller a ?crit :
> > 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 <[email protected]>
> >> ---
> >> 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: J?r?me Pouiller <[email protected]>


--
J?r?me Pouiller

2023-02-22 12:29:15

by Kalle Valo

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

Christophe JAILLET <[email protected]> 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 <[email protected]>
> Reviewed-by: Jérôme Pouiller <[email protected]>

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