[PATCH] initcall failure reporting

We presently ignore the return values from initcalls.  But that can carry
useful debugging information.  So print it out if it's non-zero.

It turns out the -ENODEV happens quite a lot, due to built-in drivers which
have no hardware to drive.  So suppress that unless initcall_debug was
specified.

Also make the warning message more friendly by printing the name of the
initcall function.

Also drop the KERN_DEBUG from the initcall_debug message.  If we specified
inticall_debug then we obviously want to see the messages.

Acked-by: Paul Jackson <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

init/main.c

@@ -571,17 +571,23 @@ static void __init do_initcalls(void)
 	int count = preempt_count();
 
 	for (call = __initcall_start; call < __initcall_end; call++) {
-		char *msg;
+		char *msg = NULL;
+		char msgbuf[40];
+		int result;
 
 		if (initcall_debug) {
-			printk(KERN_DEBUG "Calling initcall 0x%p", *call);
-			print_fn_descriptor_symbol(": %s()", (unsigned long) *call);
+			printk("Calling initcall 0x%p", *call);
+			print_fn_descriptor_symbol(": %s()",
+					(unsigned long) *call);
 			printk("\n");
 		}
 
-		(*call)();
+		result = (*call)();
 
-		msg = NULL;
+		if (result && (result != -ENODEV || initcall_debug)) {
+			sprintf(msgbuf, "error code %d", result);
+			msg = msgbuf;
+		}
 		if (preempt_count() != count) {
 			msg = "preemption imbalance";
 			preempt_count() = count;
@@ -591,8 +597,10 @@ static void __init do_initcalls(void)
 			local_irq_enable();
 		}
 		if (msg) {
-			printk(KERN_WARNING "error in initcall at 0x%p: "
-				"returned with %s\n", *call, msg);
+			printk(KERN_WARNING "initcall at 0x%p", *call);
+			print_fn_descriptor_symbol(": %s()",
+					(unsigned long) *call);
+			printk(": returned with %s\n", msg);
 		}
 	}