V4L/DVB (10275): cx18: Additional debug to display outgoing mailbox parameters

Added debug display of outgoing mailbox arguments.  Fixed a minor problem
with display of stale incoming mailbox contents, when user was not looking for
debug warnings.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-mailbox.c

@@ -98,21 +98,30 @@ static const struct cx18_api_info *find_api_info(u32 cmd)
 	return NULL;
 }
 
-static void dump_mb(struct cx18 *cx, struct cx18_mailbox *mb, char *name)
+/* Call with buf of n*11+1 bytes */
+static char *u32arr2hex(u32 data[], int n, char *buf)
 {
-	char argstr[MAX_MB_ARGUMENTS*11+1];
 	char *p;
 	int i;
 
+	for (i = 0, p = buf; i < n; i++, p += 11) {
+		/* kernel snprintf() appends '\0' always */
+		snprintf(p, 12, " %#010x", data[i]);
+	}
+	*p = '\0';
+	return buf;
+}
+
+static void dump_mb(struct cx18 *cx, struct cx18_mailbox *mb, char *name)
+{
+	char argstr[MAX_MB_ARGUMENTS*11+1];
+
 	if (!(cx18_debug & CX18_DBGFLG_API))
 		return;
 
-	for (i = 0, p = argstr; i < MAX_MB_ARGUMENTS; i++, p += 11) {
-		/* kernel snprintf() appends '\0' always */
-		snprintf(p, 12, " %#010x", mb->args[i]);
-	}
 	CX18_DEBUG_API("%s: req %#010x ack %#010x cmd %#010x err %#010x args%s"
-		"\n", name, mb->request, mb->ack, mb->cmd, mb->error, argstr);
+		       "\n", name, mb->request, mb->ack, mb->cmd, mb->error,
+		       u32arr2hex(mb->args, MAX_MB_ARGUMENTS, argstr));
 }
 
 
@@ -439,6 +448,7 @@ void cx18_api_epu_cmd_irq(struct cx18 *cx, int rpu)
 				"incoming %s to EPU mailbox (sequence no. %u)"
 				"\n",
 				rpu_str[rpu], rpu_str[rpu], order_mb->request);
+		if (cx18_debug & CX18_DBGFLG_WARN)
 			dump_mb(cx, order_mb, "incoming");
 		order->flags = CX18_F_EWO_MB_STALE_UPON_RECEIPT;
 	}
@@ -468,16 +478,24 @@ static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 	struct mutex *mb_lock;
 	long int timeout, ret;
 	int i;
+	char argstr[MAX_MB_ARGUMENTS*11+1];
 
 	if (info == NULL) {
 		CX18_WARN("unknown cmd %x\n", cmd);
 		return -EINVAL;
 	}
 
-	if (cmd == CX18_CPU_DE_SET_MDL)
-		CX18_DEBUG_HI_API("%s\n", info->name);
-	else
-		CX18_DEBUG_API("%s\n", info->name);
+	if (cx18_debug & CX18_DBGFLG_API) { /* only call u32arr2hex if needed */
+		if (cmd == CX18_CPU_DE_SET_MDL) {
+			if (cx18_debug & CX18_DBGFLG_HIGHVOL)
+				CX18_DEBUG_HI_API("%s\tcmd %#010x args%s\n",
+						info->name, cmd,
+						u32arr2hex(data, args, argstr));
+		} else
+			CX18_DEBUG_API("%s\tcmd %#010x args%s\n",
+				       info->name, cmd,
+				       u32arr2hex(data, args, argstr));
+	}
 
 	switch (info->rpu) {
 	case APU: