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serial_core: replace uart_console_enabled() with uart_console_registered()

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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>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
This commit is contained in:
John Ogness 2022-11-16 17:27:34 +01:06 committed by Petr Mladek
parent 1fd4224a6b
commit 452b9b2475
4 changed files with 17 additions and 11 deletions
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2
drivers/tty/serial/8250/8250_core.c
View File

@ -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);

2
drivers/tty/serial/pic32_uart.c
View File

@ -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.
*/

14
drivers/tty/serial/serial_core.c
View File

@ -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)

10
include/linux/serial_core.h
View File

@ -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,