[PATCH v7 6/7] serial: 8250: Add preferred console in serial8250_isa_init_ports()

Tony Lindgren
2024-03-27T11:05:34Z

Prepare 8250 ISA ports to drop kernel command line serial console
handling from console_setup().

We need to set the preferred console in serial8250_isa_init_ports()
to drop a dependency to setup_console() handling the ttyS related
quirks. Otherwise when console_setup() handles the ttyS related
options, console gets enabled only at driver probe time.

Note that this mostly affects x86 as this happens based on define
SERIAL_PORT_DFNS.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
drivers/tty/serial/8250/8250_core.c | 5 +++++
drivers/tty/serial/serial_base.h | 8 ++++++++
drivers/tty/serial/serial_base_bus.c | 21 +++++++++++++++++++++
3 files changed, 34 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -15,6 +15,7 @@
*/

#include <linux/acpi.h>
+#include <linux/cleanup.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ioport.h>
@@ -41,6 +42,8 @@

#include <asm/irq.h>

+#include "../serial_base.h" /* For serial_base_add_isa_preferred_console() */
+
#include "8250.h"

/*
@@ -563,6 +566,8 @@ static void __init serial8250_isa_init_ports(void)
port->irqflags |= irqflag;
if (serial8250_isa_config != NULL)
serial8250_isa_config(i, &up->port, &up->capabilities);
+
+ serial_base_add_isa_preferred_console(serial8250_reg.dev_name, i);
}
}

diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h
--- a/drivers/tty/serial/serial_base.h
+++ b/drivers/tty/serial/serial_base.h
@@ -51,6 +51,8 @@ void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port
int serial_base_add_preferred_console(struct uart_driver *drv,
struct uart_port *port);

+int serial_base_add_isa_preferred_console(const char *name, int idx);
+
#else

static inline
@@ -60,4 +62,10 @@ int serial_base_add_preferred_console(struct uart_driver *drv,
return 0;
}

+static inline
+int serial_base_add_isa_preferred_console(const char *name, int idx)
+{
+ return 0;
+}
+
#endif
diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
--- a/drivers/tty/serial/serial_base_bus.c
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -317,6 +317,27 @@ int serial_base_add_preferred_console(struct uart_driver *drv,
return serial_base_add_one_prefcon(port_match, drv->dev_name, port->line);
}

+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+/*
+ * Early ISA ports initialize the console before there is no struct device.
+ * This should be only called from serial8250_isa_init_preferred_console(),
+ * other callers are likely wrong and should rely on earlycon instead.
+ */
+int serial_base_add_isa_preferred_console(const char *name, int idx)
+{
+ return serial_base_add_prefcon(name, idx);
+}
+
+#else
+
+int serial_base_add_isa_preferred_console(const char *name, int idx)
+{
+ return 0;
+}
+
+#endif
+
#endif

static int serial_base_init(void)
--
2.44.0