[patch] hid: only dump report traffic with debug level 2

[patch] hid: only dump report traffic with debug level 2

[Anssi Hannula]

Currently using debug=1 with hid module prints out all sent and received
reports to the kernel log, while in many cases we only want to see the
report descriptors and hid-input mappings that are printed when a device
is probed.

Add new level debug=2, and only dump the report traffic with that level.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>

---

Index: linux-2.6.24-verbosehid/drivers/hid/hid-core.c
===================================================================
--- linux-2.6.24-verbosehid/drivers/hid/hid-core.c
+++ linux-2.6.24-verbosehid/drivers/hid/hid-core.c	2008-03-21 13:03:29.000000000 +0200
@@ -43,8 +43,8 @@
 
 #ifdef CONFIG_HID_DEBUG
 int hid_debug = 0;
-module_param_named(debug, hid_debug, bool, 0600);
-MODULE_PARM_DESC(debug, "Turn HID debugging mode on and off");
+module_param_named(debug, hid_debug, int, 0600);
+MODULE_PARM_DESC(debug, "HID debugging (0=off, 1=probing info, 2=continuous data dumping)");
 EXPORT_SYMBOL_GPL(hid_debug);
 #endif
 
Index: linux-2.6.24-verbosehid/drivers/hid/hid-debug.c
===================================================================
--- linux-2.6.24-verbosehid/drivers/hid/hid-debug.c
+++ linux-2.6.24-verbosehid/drivers/hid/hid-debug.c	2008-03-21 13:01:21.000000000 +0200
@@ -498,7 +498,7 @@
 EXPORT_SYMBOL_GPL(hid_dump_device);
 
 void hid_dump_input(struct hid_usage *usage, __s32 value) {
-	if (!hid_debug)
+	if (hid_debug < 2)
 		return;
 
 	printk(KERN_DEBUG "hid-debug: input ");


-- Anssi Hannula

Re: [patch] hid: only dump report traffic with debug level 2

[Jiri Kosina]

On Fri, 21 Mar 2008, Anssi Hannula wrote:

> Currently using debug=1 with hid module prints out all sent and received 
> reports to the kernel log, while in many cases we only want to see the 
> report descriptors and hid-input mappings that are printed when a device 
> is probed.

Hi Anssi,

thanks for your patch, I agree that making this more configurable makes 
sense.

But I would propose staying backwards compatible, i.e. debug=1 does the 
whole dump, debug=2 excludes the individual reports but still dumps the 
report descriptor and mappings etc. What do you think?

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [patch] hid: only dump report traffic with debug level 2

[Anssi Hannula]

Jiri Kosina wrote:
> On Fri, 21 Mar 2008, Anssi Hannula wrote:
> 
>> Currently using debug=1 with hid module prints out all sent and received 
>> reports to the kernel log, while in many cases we only want to see the 
>> report descriptors and hid-input mappings that are printed when a device 
>> is probed.
> 
> Hi Anssi,
> 
> thanks for your patch, I agree that making this more configurable makes 
> sense.
> 
> But I would propose staying backwards compatible, i.e. debug=1 does the 
> whole dump, debug=2 excludes the individual reports but still dumps the 
> report descriptor and mappings etc. What do you think?

Well, I think having higher debug level should mean more debugging
output and that this logic is more important than backwards
compatibility of a debug option, it is not like it is going to break any
software or so.

But I don't care too much about it, feel free to do it the other way as
well :)

-- 
Anssi Hannula

Re: [patch] hid: only dump report traffic with debug level 2

[Jiri Kosina]

On Sat, 22 Mar 2008, Anssi Hannula wrote:

> Well, I think having higher debug level should mean more debugging 
> output and that this logic is more important than backwards 
> compatibility of a debug option, it is not like it is going to break any 
> software or so.

I agee. On the other hand, I am currently quite often telling people who 
(for example) complain about non-functioning keys on some expotic keyboard 
"just modprobe the hid module with debug=1, press the non-functioning key, 
and send me dmesg output". This would now be different depending on the 
kernel version they use, which I don't like too much.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [patch] hid: only dump report traffic with debug level 2

[Anssi Hannula]

Jiri Kosina wrote:
> On Sat, 22 Mar 2008, Anssi Hannula wrote:
> 
>> Well, I think having higher debug level should mean more debugging 
>> output and that this logic is more important than backwards 
>> compatibility of a debug option, it is not like it is going to break any 
>> software or so.
> 
> I agee. On the other hand, I am currently quite often telling people who 
> (for example) complain about non-functioning keys on some expotic keyboard 
> "just modprobe the hid module with debug=1, press the non-functioning key, 
> and send me dmesg output". This would now be different depending on the 
> kernel version they use, which I don't like too much.

Wouldn't debug=2 work with older kernel versions as well?

-- 
Anssi Hannula

Re: [patch] hid: only dump report traffic with debug level 2

[Jiri Kosina]

On Sun, 23 Mar 2008, Anssi Hannula wrote:

> > I agee. On the other hand, I am currently quite often telling people 
> > who (for example) complain about non-functioning keys on some expotic 
> > keyboard "just modprobe the hid module with debug=1, press the 
> > non-functioning key, and send me dmesg output". This would now be 
> > different depending on the kernel version they use, which I don't like 
> > too much.
> Wouldn't debug=2 work with older kernel versions as well?

Of course it would, I need to have some rest, sorry for the noise :)

I will apply your patch to my tree, thanks.

-- 
Jiri Kosina
SUSE Labs