[PATCH] debug: Introduce a dev_WARN() function

[PATCH] debug: Introduce a dev_WARN() function

[Arjan van de Ven]

From: Arjan van de Ven <arjan@linux.intel.com>
Date: Fri, 19 Sep 2008 21:03:06 -0700
Subject: [PATCH] debug: Introduce a dev_WARN() function

in the line of dev_printk(), this patch introduces a dev_WARN() macro,
that takes a struct device and then a printk format/args set of arguments.
Unlike dev_printk(), the effect is that of WARN() in that a full warning
message (including filename/line, module list, versions and a backtrace)
is printed in addition to the device name and the arguments.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 include/linux/device.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index 4d8372d..2f9cdfa 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -539,6 +539,9 @@ extern const char *dev_driver_string(const struct device *dev);
 #define dev_info(dev, format, arg...)		\
 	dev_printk(KERN_INFO , dev , format , ## arg)
 
+#define dev_WARN(dev, format, arg...) \
+	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg)
+
 #ifdef DEBUG
 #define dev_dbg(dev, format, arg...)		\
 	dev_printk(KERN_DEBUG , dev , format , ## arg)
-- 
1.5.5.1


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

[PATCH] debug: use dev_WARN() rather than WARN_ON() in device_pm_add()

[Arjan van de Ven]

From: Arjan van de Ven <arjan@linux.intel.com>
Date: Fri, 19 Sep 2008 21:05:25 -0700
Subject: [PATCH] debug: use dev_WARN() rather than WARN_ON() in device_pm_add()

device_pm_add() has a WARN_ON that is showing up relatively high on
kerneloops.org, but unfortunately the WARN_ON is less than useful
in that it doesn't print any information about what device is causing
the issue.

This patch fixes this by turning the WARN_ON() into the newly
introduces dev_WARN() which will print information about the
device in question.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 drivers/base/power/main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index bf6d355..b65667f 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -83,7 +83,7 @@ void device_pm_add(struct device *dev)
 		 * transition is in progress in order to avoid leaving them
 		 * unhandled down the road
 		 */
-		WARN_ON(true);
+		dev_WARN(dev, "Parentless device registered during a PM transaction\n");
 	}
 
 	list_add_tail(&dev->power.entry, &dpm_list);
-- 
1.5.5.1



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] debug: Introduce a dev_WARN() function

[Greg KH]

On Fri, Sep 19, 2008 at 09:07:33PM -0700, Arjan van de Ven wrote:
> 
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Fri, 19 Sep 2008 21:03:06 -0700
> Subject: [PATCH] debug: Introduce a dev_WARN() function
> 
> in the line of dev_printk(), this patch introduces a dev_WARN() macro,
> that takes a struct device and then a printk format/args set of arguments.
> Unlike dev_printk(), the effect is that of WARN() in that a full warning
> message (including filename/line, module list, versions and a backtrace)
> is printed in addition to the device name and the arguments.

I like the idea, but we already have dev_warn(), so dev_WARN() might be
a bit confusing for people.

Perhaps just documenting it with a docbook tag would suffice?

thanks,

greg k-h

Re: [PATCH] debug: Introduce a dev_WARN() function

[Arjan van de Ven]

On Fri, 19 Sep 2008 21:26:30 -0700
Greg KH <greg@kroah.com> wrote:

> > in the line of dev_printk(), this patch introduces a dev_WARN()
> > macro, that takes a struct device and then a printk format/args set
> > of arguments. Unlike dev_printk(), the effect is that of WARN() in
> > that a full warning message (including filename/line, module list,
> > versions and a backtrace) is printed in addition to the device name
> > and the arguments.
> 
> I like the idea, but we already have dev_warn(), so dev_WARN() might
> be a bit confusing for people.
> 
> Perhaps just documenting it with a docbook tag would suffice?

I didn't think we could do kerneldoc for macros? But maybe I just
misremember


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] debug: Introduce a dev_WARN() function

[Randy Dunlap]

On Fri, 19 Sep 2008 23:13:04 -0700 Arjan van de Ven wrote:

> On Fri, 19 Sep 2008 21:26:30 -0700
> Greg KH <greg@kroah.com> wrote:
> 
> > > in the line of dev_printk(), this patch introduces a dev_WARN()
> > > macro, that takes a struct device and then a printk format/args set
> > > of arguments. Unlike dev_printk(), the effect is that of WARN() in
> > > that a full warning message (including filename/line, module list,
> > > versions and a backtrace) is printed in addition to the device name
> > > and the arguments.
> > 
> > I like the idea, but we already have dev_warn(), so dev_WARN() might
> > be a bit confusing for people.
> > 
> > Perhaps just documenting it with a docbook tag would suffice?
> 
> I didn't think we could do kerneldoc for macros? But maybe I just
> misremember

It works fine.


---
~Randy

Re: [PATCH] debug: Introduce a dev_WARN() function

[Arjan van de Ven]

On Fri, 19 Sep 2008 21:26:30 -0700
Greg KH <greg@kroah.com> wrote:

> On Fri, Sep 19, 2008 at 09:07:33PM -0700, Arjan van de Ven wrote:
> > 
> > From: Arjan van de Ven <arjan@linux.intel.com>
> > Date: Fri, 19 Sep 2008 21:03:06 -0700
> > Subject: [PATCH] debug: Introduce a dev_WARN() function
> > 
> > in the line of dev_printk(), this patch introduces a dev_WARN()
> > macro, that takes a struct device and then a printk format/args set
> > of arguments. Unlike dev_printk(), the effect is that of WARN() in
> > that a full warning message (including filename/line, module list,
> > versions and a backtrace) is printed in addition to the device name
> > and the arguments.
> 
> I like the idea, but we already have dev_warn(), so dev_WARN() might
> be a bit confusing for people.
> 
> Perhaps just documenting it with a docbook tag would suffice?
> 

I added a set of comments, and also ended up doing the below USB change

>From 8a2fde5066bed00906df2fff1121d361e9e552f7 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Sat, 20 Sep 2008 10:35:51 -0700
Subject: [PATCH] usb: turn dev_warn+WARN_ON combos into dev_WARN

dev_WARN is both compacter and gives better debug information
than just a WARN_ON, since people and tools will copy the device
information message together with the WARN_ON in bug reports.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 drivers/usb/host/uhci-q.c |   24 ++++++++----------------
 1 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index db64593..1f0c2cf 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -123,14 +123,10 @@ static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
 
 static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
 {
-	if (!list_empty(&td->list)) {
-		dev_warn(uhci_dev(uhci), "td %p still in list!\n", td);
-		WARN_ON(1);
-	}
-	if (!list_empty(&td->fl_list)) {
-		dev_warn(uhci_dev(uhci), "td %p still in fl_list!\n", td);
-		WARN_ON(1);
-	}
+	if (!list_empty(&td->list))
+		dev_WARN(uhci_dev(uhci), "td %p still in list!\n", td);
+	if (!list_empty(&td->fl_list))
+		dev_WARN(uhci_dev(uhci), "td %p still in fl_list!\n", td);
 
 	dma_pool_free(uhci->td_pool, td, td->dma_handle);
 }
@@ -295,10 +291,8 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 {
 	WARN_ON(qh->state != QH_STATE_IDLE && qh->udev);
-	if (!list_empty(&qh->queue)) {
-		dev_warn(uhci_dev(uhci), "qh %p list not empty!\n", qh);
-		WARN_ON(1);
-	}
+	if (!list_empty(&qh->queue))
+		dev_WARN(uhci_dev(uhci), "qh %p list not empty!\n", qh);
 
 	list_del(&qh->node);
 	if (qh->udev) {
@@ -746,11 +740,9 @@ static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 {
 	struct uhci_td *td, *tmp;
 
-	if (!list_empty(&urbp->node)) {
-		dev_warn(uhci_dev(uhci), "urb %p still on QH's list!\n",
+	if (!list_empty(&urbp->node))
+		dev_WARN(uhci_dev(uhci), "urb %p still on QH's list!\n",
 				urbp->urb);
-		WARN_ON(1);
-	}
 
 	list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
 		uhci_remove_td_from_urbp(td);
-- 
1.5.5.1



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] debug: Introduce a dev_WARN() function

[Greg KH]

On Sat, Sep 20, 2008 at 11:11:13AM -0700, Arjan van de Ven wrote:
> On Fri, 19 Sep 2008 21:26:30 -0700
> Greg KH <greg@kroah.com> wrote:
> 
> > On Fri, Sep 19, 2008 at 09:07:33PM -0700, Arjan van de Ven wrote:
> > > 
> > > From: Arjan van de Ven <arjan@linux.intel.com>
> > > Date: Fri, 19 Sep 2008 21:03:06 -0700
> > > Subject: [PATCH] debug: Introduce a dev_WARN() function
> > > 
> > > in the line of dev_printk(), this patch introduces a dev_WARN()
> > > macro, that takes a struct device and then a printk format/args set
> > > of arguments. Unlike dev_printk(), the effect is that of WARN() in
> > > that a full warning message (including filename/line, module list,
> > > versions and a backtrace) is printed in addition to the device name
> > > and the arguments.
> > 
> > I like the idea, but we already have dev_warn(), so dev_WARN() might
> > be a bit confusing for people.
> > 
> > Perhaps just documenting it with a docbook tag would suffice?
> > 
> 
> I added a set of comments, and also ended up doing the below USB change

Ok, that looks good, care to resend all of these, with the changed
original one so that I can apply them?

thanks,

greg k-h