[PATCH] Conexant 2388x: check for kthread_run

[PATCH] Conexant 2388x: check for kthread_run

[Cyrill Gorcunov]

This patch adds checking of kthread_run return code.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
Probably we could just ignore a such situation (we do
check for core->kthread value before trying to stop the
thread) but we have to leave a footmark in kernel
messages anyway I guess. Comments?

 drivers/media/video/cx88/cx88-video.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index 98fa354..2e05450 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -1881,8 +1881,15 @@ static int __devinit cx8800_initdev(struct pci_dev *pci_dev,
 	mutex_unlock(&core->lock);
 
 	/* start tvaudio thread */
-	if (core->tuner_type != TUNER_ABSENT)
+	if (core->tuner_type != TUNER_ABSENT) {
 		core->kthread = kthread_run(cx88_audio_thread, core, "cx88 tvaudio");
+		if (IS_ERR(core->kthread)) {
+			err = PTR_ERR(core->kthread);
+			printk(KERN_ERR "Failed to create cx88 audio thread, err=%d\n",
+			       err);
+			goto fail_unreg;
+		}
+	}
 	return 0;
 
 fail_unreg:

Re: [PATCH] Conexant 2388x: check for kthread_run

[Mauro Carvalho Chehab]

Hi Cyrill,

Em Qua, 2007-07-18 às 22:56 +0400, Cyrill Gorcunov escreveu:
> This patch adds checking of kthread_run return code.
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
> Probably we could just ignore a such situation (we do
> check for core->kthread value before trying to stop the
> thread) but we have to leave a footmark in kernel
> messages anyway I guess. Comments?

> +		if (IS_ERR(core->kthread)) {
> +			err = PTR_ERR(core->kthread);
> +			printk(KERN_ERR "Failed to create cx88 audio thread, err=%d\n",
> +			       err);
> +			goto fail_unreg;

I would just remove the goto from your patch. 

It is safe not starting the kernel thread, but keeping the driver
initializing.

The drawback of not having the thread is not changing to stereo on some
situations and not detecting audio standard changes (some countries may
have more than one audio standard when you changing from VHF to UHF or
on Cable TV).

-- 
Cheers,
Mauro

Re: [PATCH] Conexant 2388x: check for kthread_run

[Cyrill Gorcunov]

[Mauro Carvalho Chehab - Wed, Jul 18, 2007 at 04:25:38PM -0300]
| Hi Cyrill,
| 
| Em Qua, 2007-07-18 ??s 22:56 +0400, Cyrill Gorcunov escreveu:
| > This patch adds checking of kthread_run return code.
| > 
| > Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
| > ---
| > Probably we could just ignore a such situation (we do
| > check for core->kthread value before trying to stop the
| > thread) but we have to leave a footmark in kernel
| > messages anyway I guess. Comments?
| 
| > +		if (IS_ERR(core->kthread)) {
| > +			err = PTR_ERR(core->kthread);
| > +			printk(KERN_ERR "Failed to create cx88 audio thread, err=%d\n",
| > +			       err);
| > +			goto fail_unreg;
| 
| I would just remove the goto from your patch. 
| 
| It is safe not starting the kernel thread, but keeping the driver
| initializing.
| 
| The drawback of not having the thread is not changing to stereo on some
| situations and not detecting audio standard changes (some countries may
| have more than one audio standard when you changing from VHF to UHF or
| on Cable TV).
| 
| -- 
| Cheers,
| Mauro
| 

Hi Mauro,
thanks for the answer. Well, here is updated version.

---
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: [PATCH] Conexant 2388x: check for kthread_run

The patch adds checking of kthread_run return code
and issues a message if it fails.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

 drivers/media/video/cx88/cx88-video.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index 98fa354..06b233a 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -1881,8 +1881,14 @@ static int __devinit cx8800_initdev(struct pci_dev *pci_dev,
 	mutex_unlock(&core->lock);
 
 	/* start tvaudio thread */
-	if (core->tuner_type != TUNER_ABSENT)
+	if (core->tuner_type != TUNER_ABSENT) {
 		core->kthread = kthread_run(cx88_audio_thread, core, "cx88 tvaudio");
+		if (IS_ERR(core->kthread)) {
+			err = PTR_ERR(core->kthread);
+			printk(KERN_ERR "Failed to create cx88 audio thread, err=%d\n",
+			       err);
+		}
+	}
 	return 0;
 
 fail_unreg: