From b3f04f50d35e19a76e4e053776826215877655d7 Mon Sep 17 00:00:00 2001
From: Petr Mladek <pmladek@suse.com>
Date: Mon, 22 Nov 2021 14:26:46 +0100
Subject: [PATCH] printk/console: Rename has_preferred_console to
 need_default_console

References: SLE Realtime Extension
Patch-mainline: v5.17-rc1
Git-commit: a6953370d2fcf8c3878f1588771d20d3d972fcf3

The logic around the variable @has_preferred_console made my head
spin many times. Part of the problem is the ambiguous name.

There is the variable @preferred_console. It points to the last
non-braille console in @console_cmdline array. This array contains
consoles preferred via the command line, device tree, or SPCR.

Then there is the variable @has_preferred_console. It is set to
"true" when @preferred_console is enabled or when a console with
tty binding gets enabled by default.

It might get reset back by the magic condition:

	if (!has_preferred_console || bcon || !console_drivers)
		has_preferred_console = preferred_console >= 0;

It is a puzzle. Dumb explanation is that it gets re-evaluated
when:

	+ it was not set before (see above when it gets set)
	+ there is still an early console enabled (bcon)
	+ there is no console enabled (!console_drivers)

This is still a puzzle.

It gets more clear when we see where the value is checked. The only
meaning of the variable is to decide whether we should try to enable
the new console by default.

Rename the variable according to the single situation where
the value is checked.

The rename requires an inverted logic. Otherwise, it is a simple
search & replace. It does not change the functionality.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Link: https://lore.kernel.org/r/20211122132649.12737-3-pmladek@suse.com
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 kernel/printk/printk.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a1e49137822a..5ab79bc28610 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -285,7 +285,7 @@ static struct console *exclusive_console;
 static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
 
 static int preferred_console = -1;
-static bool has_preferred_console;
+static bool need_default_console = true;
 int console_set_on_cmdline;
 EXPORT_SYMBOL(console_set_on_cmdline);
 
@@ -2960,7 +2960,7 @@ static int try_enable_preferred_console(struct console *newcon,
 		newcon->flags |= CON_ENABLED;
 		if (i == preferred_console) {
 			newcon->flags |= CON_CONSDEV;
-			has_preferred_console = true;
+			need_default_console = false;
 		}
 		return 0;
 	}
@@ -2989,7 +2989,7 @@ static void try_enable_default_console(struct console *newcon)
 
 	if (newcon->device) {
 		newcon->flags |= CON_CONSDEV;
-		has_preferred_console = true;
+		need_default_console = false;
 	}
 }
 
@@ -3040,15 +3040,15 @@ void register_console(struct console *newcon)
 	if (console_drivers && console_drivers->flags & CON_BOOT)
 		bcon = console_drivers;
 
-	if (!has_preferred_console || bcon || !console_drivers)
-		has_preferred_console = preferred_console >= 0;
+	if (need_default_console || bcon || !console_drivers)
+		need_default_console = preferred_console < 0;
 
 	/*
 	 *	See if we want to use this console driver. If we
 	 *	didn't select a console we take the first one
 	 *	that registers here.
 	 */
-	if (!has_preferred_console)
+	if (need_default_console)
 		try_enable_default_console(newcon);
 
 	/* See if this console matches one we selected on the command line */