Thread (17 messages) 17 messages, 7 authors, 2017-03-15

Re: [PATCH v3 3/3] printk: fix double printing with earlycon

From: Sergey Senozhatsky <hidden>
Date: 2017-03-06 15:06:52
Also in: lkml

On (03/03/17 18:49), Aleksey Makarov wrote:
[..]
+static enum { CONSOLE_MATCH, CONSOLE_MATCH_RETURN, CONSOLE_MATCH_NEXT }
+match_console(struct console *newcon, struct console_cmdline *c)
that enum in function return is interesting :)
can we make it less hackish?
+	if (!newcon->match ||
+	    newcon->match(newcon, c->name, c->index, c->options) != 0) {
+		/* default matching */
+		BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
+		if (strcmp(c->name, newcon->name) != 0)
+			return CONSOLE_MATCH_NEXT;
+		if (newcon->index >= 0 && newcon->index != c->index)
+			return CONSOLE_MATCH_NEXT;
who is checking CONSOLE_MATCH_NEXT?
quoted hunk ↗ jump to hunk
+		if (newcon->index < 0)
+			newcon->index = c->index;
+
+		if (_braille_register_console(newcon, c))
+			return CONSOLE_MATCH_RETURN;
+
+		if (newcon->setup &&
+		    newcon->setup(newcon, c->options) != 0)
+			return CONSOLE_MATCH;
+	}
+
+	newcon->flags |= CON_ENABLED;
+	return CONSOLE_MATCH;
+}
+
 /*
  * The console driver calls this routine during kernel initialization
  * to register the console printing procedure with printk() and to
@@ -2454,40 +2480,50 @@ void register_console(struct console *newcon)
 	}
 
 	/*
+	 * Check if this console was set as preferred by command line parameters
+	 * or by call to add_preferred_console().  There may be several entries
+	 * in the console_cmdline array matching with the same console so we
+	 * can not just use the first match.  Instead check the entry pointed
+	 * by preferred_console and then all other entries.
+	 */
+	if (preferred_console >= 0) {
+		switch (match_console(newcon,
+				      console_cmdline + preferred_console)) {
+		case CONSOLE_MATCH:
+			if (newcon->flags | CON_ENABLED) {
			newcon->flags & CON_ENABLED  ?
+				newcon->flags |= CON_CONSDEV;
+				has_preferred = true;
+			}
+			goto match;
+		case CONSOLE_MATCH_RETURN:
+			return;
+		default:
+			break;
+		}
+	}
+
+	/*
 	 *	See if this console matches one we selected on
 	 *	the command line.
 	 */
 	for (i = 0, c = console_cmdline;
 	     i < MAX_CMDLINECONSOLES && c->name[0];
 	     i++, c++) {
-		if (!newcon->match ||
-		    newcon->match(newcon, c->name, c->index, c->options) != 0) {
-			/* default matching */
-			BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
-			if (strcmp(c->name, newcon->name) != 0)
-				continue;
-			if (newcon->index >= 0 &&
-			    newcon->index != c->index)
-				continue;
-			if (newcon->index < 0)
-				newcon->index = c->index;
-
-			if (_braille_register_console(newcon, c))
-				return;
 
-			if (newcon->setup &&
-			    newcon->setup(newcon, c->options) != 0)
-				break;
-		}
+		if (preferred_console == i)
+			continue;
 
-		newcon->flags |= CON_ENABLED;
-		if (i == preferred_console) {
-			newcon->flags |= CON_CONSDEV;
-			has_preferred = true;
+		switch (match_console(newcon, c)) {
+		case CONSOLE_MATCH:
+			goto match;
+		case CONSOLE_MATCH_RETURN:
+			return;
+		default:
+			break;
sorry, it was a rather long for me today. need to look more at this.
for what is now CONSOLE_MATCH_NEXT we used to have continue, and now
we break out of the loop?

	-ss
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help