HID: make debugging output runtime-configurable

There have been many reports recently about broken HID devices, the
diagnosis of which required users to recompile their kernels in order
to be able to provide debugging output needed for coding a quirk for
a particular device.

This patch makes CONFIG_HID_DEBUG default y if !EMBEDDED and makes it
possible to control debugging output produced by HID code by supplying
'debug=1' module parameter.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 15 insertions, 5 deletions

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 827ee748fd4c..eb53d9a9ae54 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -488,6 +488,11 @@ struct hid_descriptor {
 #define IS_INPUT_APPLICATION(a) (((a >= 0x00010000) && (a <= 0x00010008)) || (a == 0x00010080) || (a == 0x000c0001))
 
 /* HID core API */
+
+#ifdef CONFIG_HID_DEBUG
+extern int hid_debug;
+#endif
+
 extern void hidinput_hid_event(struct hid_device *, struct hid_field *, struct hid_usage *, __s32);
 extern void hidinput_report_event(struct hid_device *hid, struct hid_report *report);
 extern int hidinput_connect(struct hid_device *);
@@ -523,14 +528,19 @@ static inline int hid_pidff_init(struct hid_device *hid) { return -ENODEV; }
 #else
 static inline int hid_ff_init(struct hid_device *hid) { return -1; }
 #endif
-#ifdef DEBUG
-#define dbg(format, arg...) printk(KERN_DEBUG "%s: " format "\n" , \
-                __FILE__ , ## arg)
+
+#ifdef CONFIG_HID_DEBUG
+#define dbg_hid(format, arg...) if (hid_debug) \
+                                printk(KERN_DEBUG "%s: " format ,\
+                                __FILE__ , ## arg)
+#define dbg_hid_line(format, arg...) if (hid_debug) \
+                                printk(format, ## arg)
 #else
-#define dbg(format, arg...) do {} while (0)
+#define dbg_hid(format, arg...) do {} while (0)
+#define dbg_hid_line dbg_hid
 #endif
 
-#define err(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
+#define err_hid(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
                 __FILE__ , ## arg)
 #endif