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Subject[PATCH printk v5 22/40] serial_core: replace uart_console_enabled() with uart_console_registered()
Date
All users of uart_console_enabled() really want to know if a console
is registered. It is not reliable to check for CON_ENABLED in order
to identify if a console is registered. Use console_is_registered()
instead.

A _locked() variant is provided because uart_set_options() is always
called with the console_list_lock held and must check if a console
is registered in order to synchronize with kgdboc.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
drivers/tty/serial/8250/8250_core.c | 2 +-
drivers/tty/serial/pic32_uart.c | 2 +-
drivers/tty/serial/serial_core.c | 14 +++++++-------
include/linux/serial_core.h | 10 ++++++++--
4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 94fbf0add2ce..74568292186f 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -565,7 +565,7 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)

up->port.dev = dev;

- if (uart_console_enabled(&up->port))
+ if (uart_console_registered(&up->port))
pm_runtime_get_sync(up->port.dev);

serial8250_apply_quirks(up);
diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c
index 2beada66c824..1183b2a26539 100644
--- a/drivers/tty/serial/pic32_uart.c
+++ b/drivers/tty/serial/pic32_uart.c
@@ -919,7 +919,7 @@ static int pic32_uart_probe(struct platform_device *pdev)
}

#ifdef CONFIG_SERIAL_PIC32_CONSOLE
- if (uart_console_enabled(port)) {
+ if (uart_console_registered(port)) {
/* The peripheral clock has been enabled by console_setup,
* so disable it till the port is used.
*/
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 179ee199df34..b9fbbee598b8 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2223,11 +2223,11 @@ uart_set_options(struct uart_port *port, struct console *co,
/*
* Ensure that the serial-console lock is initialised early.
*
- * Note that the console-enabled check is needed because of kgdboc,
- * which can end up calling uart_set_options() for an already enabled
+ * Note that the console-registered check is needed because
+ * kgdboc can call uart_set_options() for an already registered
* console via tty_find_polling_driver() and uart_poll_init().
*/
- if (!uart_console_enabled(port) && !port->console_reinit)
+ if (!uart_console_registered_locked(port) && !port->console_reinit)
uart_port_spin_lock_init(port);

memset(&termios, 0, sizeof(struct ktermios));
@@ -2573,7 +2573,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
* successfully registered yet, try to re-register it.
* It may be that the port was not available.
*/
- if (port->cons && !(port->cons->flags & CON_ENABLED))
+ if (port->cons && !console_is_registered(port->cons))
register_console(port->cons);

/*
@@ -2956,7 +2956,7 @@ static ssize_t console_show(struct device *dev,
mutex_lock(&port->mutex);
uport = uart_port_check(state);
if (uport)
- console = uart_console_enabled(uport);
+ console = uart_console_registered(uport);
mutex_unlock(&port->mutex);

return sprintf(buf, "%c\n", console ? 'Y' : 'N');
@@ -2978,7 +2978,7 @@ static ssize_t console_store(struct device *dev,
mutex_lock(&port->mutex);
uport = uart_port_check(state);
if (uport) {
- oldconsole = uart_console_enabled(uport);
+ oldconsole = uart_console_registered(uport);
if (oldconsole && !newconsole) {
ret = unregister_console(uport->cons);
} else if (!oldconsole && newconsole) {
@@ -3086,7 +3086,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
* If this port is in use as a console then the spinlock is already
* initialised.
*/
- if (!uart_console_enabled(uport))
+ if (!uart_console_registered(uport))
uart_port_spin_lock_init(uport);

if (uport->cons && uport->dev)
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index d657f2a42a7b..91871464b99d 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -743,9 +743,15 @@ static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
static inline int setup_earlycon(char *buf) { return 0; }
#endif

-static inline bool uart_console_enabled(struct uart_port *port)
+/* Variant of uart_console_registered() when the console_list_lock is held. */
+static inline bool uart_console_registered_locked(struct uart_port *port)
{
- return uart_console(port) && (port->cons->flags & CON_ENABLED);
+ return uart_console(port) && console_is_registered_locked(port->cons);
+}
+
+static inline bool uart_console_registered(struct uart_port *port)
+{
+ return uart_console(port) && console_is_registered(port->cons);
}

struct uart_port *uart_get_console(struct uart_port *ports, int nr,
--
2.30.2
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