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authorPetr Mladek <pmladek@suse.com>2022-01-10 12:15:08 +0100
committerPetr Mladek <pmladek@suse.com>2022-01-10 12:15:08 +0100
commitd12013c80e1524e3e85c01d50adcefd70b1a8b6f (patch)
treee4da6d31c2ce3d4bc18b39325741f23c9d5234ba
parent73d86812a35965a3eab179abb462b77b4dd8a740 (diff)
parent5e8ba485b2522808ab2d65208839e1c915e113dd (diff)
Merge branch 'console-registration-cleanup' into for-linus
-rw-r--r--kernel/printk/printk.c104
1 files changed, 58 insertions, 46 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 57b132b658e1..155229f0cf0f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -280,7 +280,6 @@ static struct console *exclusive_console;
static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
static int preferred_console = -1;
-static bool has_preferred_console;
int console_set_on_cmdline;
EXPORT_SYMBOL(console_set_on_cmdline);
@@ -2861,7 +2860,8 @@ early_param("keep_bootcon", keep_bootcon_setup);
* Care need to be taken with consoles that are statically
* enabled such as netconsole
*/
-static int try_enable_new_console(struct console *newcon, bool user_specified)
+static int try_enable_preferred_console(struct console *newcon,
+ bool user_specified)
{
struct console_cmdline *c;
int i, err;
@@ -2891,10 +2891,8 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
return err;
}
newcon->flags |= CON_ENABLED;
- if (i == preferred_console) {
+ if (i == preferred_console)
newcon->flags |= CON_CONSDEV;
- has_preferred_console = true;
- }
return 0;
}
@@ -2909,6 +2907,21 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
return -ENOENT;
}
+/* Try to enable the console unconditionally */
+static void try_enable_default_console(struct console *newcon)
+{
+ if (newcon->index < 0)
+ newcon->index = 0;
+
+ if (newcon->setup && newcon->setup(newcon, NULL) != 0)
+ return;
+
+ newcon->flags |= CON_ENABLED;
+
+ if (newcon->device)
+ newcon->flags |= CON_CONSDEV;
+}
+
/*
* The console driver calls this routine during kernel initialization
* to register the console printing procedure with printk() and to
@@ -2930,59 +2943,56 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
*/
void register_console(struct console *newcon)
{
- struct console *bcon = NULL;
+ struct console *con;
+ bool bootcon_enabled = false;
+ bool realcon_enabled = false;
int err;
- for_each_console(bcon) {
- if (WARN(bcon == newcon, "console '%s%d' already registered\n",
- bcon->name, bcon->index))
+ for_each_console(con) {
+ if (WARN(con == newcon, "console '%s%d' already registered\n",
+ con->name, con->index))
return;
}
- /*
- * before we register a new CON_BOOT console, make sure we don't
- * already have a valid console
- */
- if (newcon->flags & CON_BOOT) {
- for_each_console(bcon) {
- if (!(bcon->flags & CON_BOOT)) {
- pr_info("Too late to register bootconsole %s%d\n",
- newcon->name, newcon->index);
- return;
- }
- }
+ for_each_console(con) {
+ if (con->flags & CON_BOOT)
+ bootcon_enabled = true;
+ else
+ realcon_enabled = true;
}
- if (console_drivers && console_drivers->flags & CON_BOOT)
- bcon = console_drivers;
-
- if (!has_preferred_console || bcon || !console_drivers)
- has_preferred_console = preferred_console >= 0;
+ /* Do not register boot consoles when there already is a real one. */
+ if (newcon->flags & CON_BOOT && realcon_enabled) {
+ pr_info("Too late to register bootconsole %s%d\n",
+ newcon->name, newcon->index);
+ return;
+ }
/*
- * See if we want to use this console driver. If we
- * didn't select a console we take the first one
- * that registers here.
+ * See if we want to enable this console driver by default.
+ *
+ * Nope when a console is preferred by the command line, device
+ * tree, or SPCR.
+ *
+ * The first real console with tty binding (driver) wins. More
+ * consoles might get enabled before the right one is found.
+ *
+ * Note that a console with tty binding will have CON_CONSDEV
+ * flag set and will be first in the list.
*/
- if (!has_preferred_console) {
- if (newcon->index < 0)
- newcon->index = 0;
- if (newcon->setup == NULL ||
- newcon->setup(newcon, NULL) == 0) {
- newcon->flags |= CON_ENABLED;
- if (newcon->device) {
- newcon->flags |= CON_CONSDEV;
- has_preferred_console = true;
- }
+ if (preferred_console < 0) {
+ if (!console_drivers || !console_drivers->device ||
+ console_drivers->flags & CON_BOOT) {
+ try_enable_default_console(newcon);
}
}
/* See if this console matches one we selected on the command line */
- err = try_enable_new_console(newcon, true);
+ err = try_enable_preferred_console(newcon, true);
/* If not, try to match against the platform default(s) */
if (err == -ENOENT)
- err = try_enable_new_console(newcon, false);
+ err = try_enable_preferred_console(newcon, false);
/* printk() messages are not printed to the Braille console. */
if (err || newcon->flags & CON_BRL)
@@ -2994,8 +3004,10 @@ void register_console(struct console *newcon)
* the real console are the same physical device, it's annoying to
* see the beginning boot messages twice
*/
- if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV))
+ if (bootcon_enabled &&
+ ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) {
newcon->flags &= ~CON_PRINTBUFFER;
+ }
/*
* Put this console in the list - keep the
@@ -3051,15 +3063,15 @@ void register_console(struct console *newcon)
pr_info("%sconsole [%s%d] enabled\n",
(newcon->flags & CON_BOOT) ? "boot" : "" ,
newcon->name, newcon->index);
- if (bcon &&
+ if (bootcon_enabled &&
((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV) &&
!keep_bootcon) {
/* We need to iterate through all boot consoles, to make
* sure we print everything out, before we unregister them.
*/
- for_each_console(bcon)
- if (bcon->flags & CON_BOOT)
- unregister_console(bcon);
+ for_each_console(con)
+ if (con->flags & CON_BOOT)
+ unregister_console(con);
}
}
EXPORT_SYMBOL(register_console);