[PATCH v3 0/7] serial: Some yak shaving

[PATCH v3 0/7] serial: Some yak shaving

[Uwe Kleine-König (The Capable Hub)]

Hello,

v2 of this series can be found at
https://lore.kernel.org/linux-serial/cover.1785832297.git.u.kleine-koenig@baylibre.com
. Changes since then:

 - Drop "serial: txx9: Simplify knowing that .iotype is always
   UPIO_PORT" as the assumption that .iotype is always UPIO_PORT proved
   to be wrong. Thanks to Atsushi Nemoto and Geert Uytterhoeven for
   finding and proving that.
 - Reworked commit log of "serial: txx9: Drop usage of
   uart_match_port()" and add a code comment to justify the comparison.
 - Fix a build issue in "serial: 8250: hub6: Add cleanup code"
 - Added tags received in v2. Andy liked the v2 series in reply to the
   cover letter. I applied his Ack to all patches but "serial: txx9:
   Drop usage of uart_match_port()" as this changed. I would expect he
   agrees to this patch, too, but I'm conservative here.
 - (trivially) rebase to yesterday's next
 - Drop Alan Cox from Cc:, fix email address for Russell King

Best regards
Uwe

Uwe Kleine-König (The Capable Hub) (7):
  serial: txx9: Drop noop probe function and dangerous remove callback
  serial: txx9: Drop usage of uart_match_port()
  serial: 8250: Make uart_match_port() a 8250 specific function
  serial: 8250: Simplify serial8250_match_port()
  serial: 8250: Fix corner case for port matching
  serial: 8250: hub6: Add cleanup code
  serial: 8250: pnp: Annotate init and exit functions for conditional
    discarding

 Documentation/driver-api/serial/driver.rst |  2 +-
 drivers/tty/serial/8250/8250.h             | 10 +++-
 drivers/tty/serial/8250/8250_core.c        | 25 ++++++++-
 drivers/tty/serial/8250/8250_hub6.c        | 11 ++--
 drivers/tty/serial/8250/8250_platform.c    |  9 +++-
 drivers/tty/serial/8250/8250_pnp.c         |  4 +-
 drivers/tty/serial/8250/Kconfig            |  4 +-
 drivers/tty/serial/8250/Makefile           |  2 +-
 drivers/tty/serial/serial_core.c           | 27 ----------
 drivers/tty/serial/serial_txx9.c           | 62 ++++------------------
 include/linux/serial_core.h                |  2 -
 11 files changed, 61 insertions(+), 97 deletions(-)


base-commit: 2697ef8943c9985c14708a6429e21812693857b2
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 1/7] serial: txx9: Drop noop probe function and dangerous remove callback

[Uwe Kleine-König (The Capable Hub)]

The only platform device that can be bound to the driver is allocated by
the driver itself. That device doesn't have platdata, so the probe
function only consists of a loop that is never run and thus can be
dropped without loss of functionality.

The remove function then should better not undo things that were not
done in the first place. That happens because serial_txx9_init() calls
serial_txx9_register_ports() with the created platform device and so
up->dev == &dev->dev evaluates to true and uart_remove_one_port() is
called twice for each port.

So let serial_txx9_exit() undo exactly what serial_txx9_init() does and
remove the useless respectively wrong functions.

Fixes: 0970769aceb9 ("[SERIAL] serial_txx9 driver update")
Reviewed-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/serial_txx9.c | 55 ++------------------------------
 1 file changed, 3 insertions(+), 52 deletions(-)

diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index 4ae9a45c8e3a..ef56979321b9 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -1009,7 +1009,8 @@ static void serial_txx9_unregister_port(int line)
 	struct uart_port *uart = &serial_txx9_ports[line];
 
 	mutex_lock(&serial_txx9_mutex);
-	uart_remove_one_port(&serial_txx9_reg, uart);
+	if (uart->iobase || uart->mapbase)
+		uart_remove_one_port(&serial_txx9_reg, uart);
 	uart->flags = 0;
 	uart->type = PORT_UNKNOWN;
 	uart->iobase = 0;
@@ -1019,52 +1020,6 @@ static void serial_txx9_unregister_port(int line)
 	mutex_unlock(&serial_txx9_mutex);
 }
 
-/*
- * Register a set of serial devices attached to a platform device.
- */
-static int serial_txx9_probe(struct platform_device *dev)
-{
-	struct uart_port *p = dev_get_platdata(&dev->dev);
-	struct uart_port port;
-	int ret, i;
-
-	memset(&port, 0, sizeof(struct uart_port));
-	for (i = 0; p && p->uartclk != 0; p++, i++) {
-		port.iobase	= p->iobase;
-		port.membase	= p->membase;
-		port.irq	= p->irq;
-		port.uartclk	= p->uartclk;
-		port.iotype	= p->iotype;
-		port.flags	= p->flags;
-		port.mapbase	= p->mapbase;
-		port.dev	= &dev->dev;
-		port.has_sysrq	= IS_ENABLED(CONFIG_SERIAL_TXX9_CONSOLE);
-		ret = serial_txx9_register_port(&port);
-		if (ret < 0) {
-			dev_err(&dev->dev, "unable to register port at index %d "
-				"(IO%lx MEM%llx IRQ%d): %d\n", i,
-				p->iobase, (unsigned long long)p->mapbase,
-				p->irq, ret);
-		}
-	}
-	return 0;
-}
-
-/*
- * Remove serial ports registered against a platform device.
- */
-static void serial_txx9_remove(struct platform_device *dev)
-{
-	int i;
-
-	for (i = 0; i < UART_NR; i++) {
-		struct uart_port *up = &serial_txx9_ports[i];
-
-		if (up->dev == &dev->dev)
-			serial_txx9_unregister_port(i);
-	}
-}
-
 #ifdef CONFIG_PM
 static int serial_txx9_suspend(struct platform_device *dev, pm_message_t state)
 {
@@ -1096,8 +1051,6 @@ static int serial_txx9_resume(struct platform_device *dev)
 #endif
 
 static struct platform_driver serial_txx9_plat_driver = {
-	.probe		= serial_txx9_probe,
-	.remove		= serial_txx9_remove,
 #ifdef CONFIG_PM
 	.suspend	= serial_txx9_suspend,
 	.resume		= serial_txx9_resume,
@@ -1251,9 +1204,7 @@ static void __exit serial_txx9_exit(void)
 	platform_driver_unregister(&serial_txx9_plat_driver);
 	platform_device_unregister(serial_txx9_plat_devs);
 	for (i = 0; i < UART_NR; i++) {
-		struct uart_port *up = &serial_txx9_ports[i];
-		if (up->iobase || up->mapbase)
-			uart_remove_one_port(&serial_txx9_reg, up);
+		serial_txx9_unregister_port(i);
 	}
 
 	uart_unregister_driver(&serial_txx9_reg);
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 2/7] serial: txx9: Drop usage of uart_match_port()

[Uwe Kleine-König (The Capable Hub)]

Where the uart_match_port() function is used it's known that .iotype is
UPIO_PORT. So uart_match_port() is equivalent to comparing .iobase.
Remove the call to uart_match_port() which then only has a single caller
that is handled in the next commit.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/serial_txx9.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index ef56979321b9..5b574ed276b2 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -965,7 +965,12 @@ static int serial_txx9_register_port(struct uart_port *port)
 	mutex_lock(&serial_txx9_mutex);
 	for (i = 0; i < UART_NR; i++) {
 		uart = &serial_txx9_ports[i];
-		if (uart_match_port(uart, port)) {
+		/*
+		 * serial_txx9_register_port() is only called from
+		 * pciserial_txx9_init_one(). So .iotype is UPIO_PORT and
+		 * comparing .iobase serves to distinguish ports.
+		 */
+		if (uart->iobase == port->iobase) {
 			uart_remove_one_port(&serial_txx9_reg, uart);
 			break;
 		}
-- 
2.55.0.11.g153666a7d9bb

Re: [PATCH v3 2/7] serial: txx9: Drop usage of uart_match_port()

[Geert Uytterhoeven]

On Fri, 14 Aug 2026 at 11:19, Uwe Kleine-König (The Capable Hub)
<u.kleine-koenig@baylibre.com> wrote:
> Where the uart_match_port() function is used it's known that .iotype is
> UPIO_PORT. So uart_match_port() is equivalent to comparing .iobase.
> Remove the call to uart_match_port() which then only has a single caller
> that is handled in the next commit.
>
> Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

I don't have the TC86C001FG PCI device (which is presumable present
on the GOKU-S sub-board), so I cannot test this code path.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH v3 3/7] serial: 8250: Make uart_match_port() a 8250 specific function

[Uwe Kleine-König (The Capable Hub)]

The 8250 driver conglomerate is the only user of uart_match_port() and
in fact it already is 8250 specific as it uses hub6_match_port() which
is defined in drivers/tty/serial/8250/8250_hub6.c unless the dummy
implementation is in use.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 Documentation/driver-api/serial/driver.rst |  2 +-
 drivers/tty/serial/8250/8250_core.c        | 27 +++++++++++++++++++++-
 drivers/tty/serial/serial_core.c           | 27 ----------------------
 include/linux/serial_core.h                |  2 --
 4 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/Documentation/driver-api/serial/driver.rst b/Documentation/driver-api/serial/driver.rst
index c1db6a1a67c4..975b0ba53e98 100644
--- a/Documentation/driver-api/serial/driver.rst
+++ b/Documentation/driver-api/serial/driver.rst
@@ -70,7 +70,7 @@ Other functions
 
 .. kernel-doc:: drivers/tty/serial/serial_core.c
    :identifiers: uart_update_timeout uart_get_baud_rate uart_get_divisor
-           uart_match_port uart_write_wakeup uart_register_driver
+           uart_write_wakeup uart_register_driver
            uart_unregister_driver uart_suspend_port uart_resume_port
            uart_add_one_port uart_remove_one_port uart_console_write
            uart_parse_earlycon uart_parse_options uart_set_options
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index b875d394796f..d8199c583830 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -673,6 +673,31 @@ EXPORT_SYMBOL(serial8250_resume_port);
  */
 static DEFINE_MUTEX(serial_mutex);
 
+/**
+ * serial8250_match_port - are the two ports equivalent?
+ * @port1: first port
+ * @port2: second port
+ *
+ * This utility function can be used to determine whether two uart_port
+ * structures describe the same port.
+ */
+static bool serial8250_match_port(const struct uart_port *port1,
+				  const struct uart_port *port2)
+{
+	if (port1->iotype != port2->iotype)
+		return false;
+	else if (port1->iotype == UPIO_PORT)
+		return port1->iobase == port2->iobase;
+	else if (port1->iotype == UPIO_HUB6)
+		return hub6_match_port(port1, port2);
+	else if (uart_iotype_mmio(port1->iotype))
+		return port1->mapbase == port2->mapbase;
+	else if (port1->iotype == UPIO_BUS)
+		return true;
+	else
+		return false;
+}
+
 static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_port *port)
 {
 	int i;
@@ -681,7 +706,7 @@ static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_
 	 * First, find a port entry which matches.
 	 */
 	for (i = 0; i < nr_uarts; i++)
-		if (uart_match_port(&serial8250_ports[i].port, port))
+		if (serial8250_match_port(&serial8250_ports[i].port, port))
 			return &serial8250_ports[i];
 
 	/* try line number first if still available */
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 95774b0f1484..ee75f53979bd 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -33,7 +33,6 @@
 #include <linux/uaccess.h>
 
 #include "serial_base.h"
-#include "8250/8250.h" /* For hub6_match_port() */
 
 /*
  * This is used to lock changes in serial line configuration.
@@ -3233,32 +3232,6 @@ static void serial_core_remove_one_port(struct uart_driver *drv,
 	state->uart_port = NULL;
 }
 
-/**
- * uart_match_port - are the two ports equivalent?
- * @port1: first port
- * @port2: second port
- *
- * This utility function can be used to determine whether two uart_port
- * structures describe the same port.
- */
-bool uart_match_port(const struct uart_port *port1,
-		const struct uart_port *port2)
-{
-	if (port1->iotype != port2->iotype)
-		return false;
-	else if (port1->iotype == UPIO_PORT)
-		return port1->iobase == port2->iobase;
-	else if (port1->iotype == UPIO_HUB6)
-		return hub6_match_port(port1, port2);
-	else if (uart_iotype_mmio(port1->iotype))
-		return port1->mapbase == port2->mapbase;
-	else if (port1->iotype == UPIO_BUS)
-		return true;
-	else
-		return false;
-}
-EXPORT_SYMBOL(uart_match_port);
-
 static struct serial_ctrl_device *
 serial_core_get_ctrl_dev(struct serial_port_device *port_dev)
 {
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 904760876ca8..4eeb8253752a 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -1140,8 +1140,6 @@ int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 int uart_read_port_properties(struct uart_port *port);
 int uart_read_and_validate_port_properties(struct uart_port *port);
-bool uart_match_port(const struct uart_port *port1,
-		const struct uart_port *port2);
 
 /*
  * Power Management
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 4/7] serial: 8250: Simplify serial8250_match_port()

[Uwe Kleine-König (The Capable Hub)]

For 8250 devices .iotype is never UPIO_BUS, so drop the respective if
branch.

Suggested-by: Hugo Villeneuve <hugo@hugovil.com>
Link: https://lore.kernel.org/linux-serial/20260803152228.9e3cd296a41e68304b82a22a@hugovil.com
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/8250/8250_core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index d8199c583830..11424fef7c08 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -692,8 +692,6 @@ static bool serial8250_match_port(const struct uart_port *port1,
 		return hub6_match_port(port1, port2);
 	else if (uart_iotype_mmio(port1->iotype))
 		return port1->mapbase == port2->mapbase;
-	else if (port1->iotype == UPIO_BUS)
-		return true;
 	else
 		return false;
 }
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 5/7] serial: 8250: Fix corner case for port matching

[Uwe Kleine-König (The Capable Hub)]

In the case CONFIG_SERIAL_8250=y + CONFIG_SERIAL_8250_HUB6=m
hub6_match_port() evaluates statically to false in
serial8250_match_port() which is a bug and a change in behavior compared
to before commit 7ab80d1e7243 ("serial: 8250: fix compile error with
hub6_match_port() when compiled as a module").

To make the comparison correct, the dummy implementation of
hub6_match_port() must only be used if CONFIG_SERIAL_8250_HUB6 is
disabled. Then as there is a bidirectional dependency between
8250_hub6.c and 8250_core.c, put both in the same module.

Fixes: 7ab80d1e7243 ("serial: 8250: fix compile error with hub6_match_port() when compiled as a module")
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/8250/8250.h          | 8 +++++++-
 drivers/tty/serial/8250/8250_hub6.c     | 8 +-------
 drivers/tty/serial/8250/8250_platform.c | 4 ++++
 drivers/tty/serial/8250/Kconfig         | 4 ++--
 drivers/tty/serial/8250/Makefile        | 2 +-
 5 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 9337fec9394e..3fd25b7a7b81 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -316,6 +316,12 @@ static inline int serial8250_pnp_init(void) { return 0; }
 static inline void serial8250_pnp_exit(void) { }
 #endif
 
+#ifdef CONFIG_SERIAL_8250_HUB6
+int serial8250_hub6_init(void);
+#else
+static inline int serial8250_hub6_init(void) { return 0; }
+#endif
+
 #ifdef CONFIG_SERIAL_8250_RSA
 void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops);
 void rsa_enable(struct uart_8250_port *up);
@@ -336,7 +342,7 @@ int fintek_8250_probe(struct uart_8250_port *uart);
 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
 #endif
 
-#if IS_REACHABLE(CONFIG_SERIAL_8250_HUB6)
+#if IS_ENABLED(CONFIG_SERIAL_8250_HUB6)
 bool hub6_match_port(const struct uart_port *port1, const struct uart_port *port2);
 #else
 static inline bool hub6_match_port(const struct uart_port *port1, const struct uart_port *port2)
diff --git a/drivers/tty/serial/8250/8250_hub6.c b/drivers/tty/serial/8250/8250_hub6.c
index b6767633c966..3e548530ec4e 100644
--- a/drivers/tty/serial/8250/8250_hub6.c
+++ b/drivers/tty/serial/8250/8250_hub6.c
@@ -49,13 +49,7 @@ bool hub6_match_port(const struct uart_port *port1, const struct uart_port *port
 }
 EXPORT_SYMBOL_GPL(hub6_match_port);
 
-static int __init hub6_init(void)
+int __init serial8250_hub6_init(void)
 {
 	return platform_device_register(&hub6_device);
 }
-
-module_init(hub6_init);
-
-MODULE_AUTHOR("Russell King");
-MODULE_DESCRIPTION("8250 serial probe module for Hub6 cards");
-MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c
index af946d12e764..3a2dff9ce7b7 100644
--- a/drivers/tty/serial/8250/8250_platform.c
+++ b/drivers/tty/serial/8250/8250_platform.c
@@ -319,6 +319,10 @@ static int __init serial8250_init(void)
 	if (ret)
 		goto unreg_uart_drv;
 
+	ret = serial8250_hub6_init();
+	if (ret)
+		goto unreg_pnp;
+
 	serial8250_isa_devs = platform_device_alloc("serial8250", PLAT8250_DEV_LEGACY);
 	if (!serial8250_isa_devs) {
 		ret = -ENOMEM;
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index fa6f33303cb0..1d3f7e57e959 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -304,8 +304,8 @@ config SERIAL_8250_EXAR_ST16C554
 	  will be called 8250_exar_st16c554.
 
 config SERIAL_8250_HUB6
-	tristate "Support Hub6 cards"
-	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	bool "Support Hub6 cards"
+	depends on SERIAL_8250_MANY_PORTS && ISA
 	help
 	  Say Y here if you have a HUB6 serial board.
 
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 46adadcfe072..330dd6cf7c83 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SERIAL_8250)		+= 8250.o
 8250-y					:= 8250_core.o
 8250-y					+= 8250_platform.o
 8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o
+8250-$(CONFIG_SERIAL_8250_HUB6)		+= 8250_hub6.o
 
 obj-$(CONFIG_SERIAL_8250)		+= 8250_base.o
 8250_base-y				:= 8250_port.o
@@ -35,7 +36,6 @@ obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554)	+= 8250_exar_st16c554.o
 obj-$(CONFIG_SERIAL_8250_FOURPORT)	+= 8250_fourport.o
 obj-$(CONFIG_SERIAL_8250_FSL)		+= 8250_fsl.o
 obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o
-obj-$(CONFIG_SERIAL_8250_HUB6)		+= 8250_hub6.o
 obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
 obj-$(CONFIG_SERIAL_8250_IOC3)		+= 8250_ioc3.o
 obj-$(CONFIG_SERIAL_8250_KEBA)		+= 8250_keba.o
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 6/7] serial: 8250: hub6: Add cleanup code

[Uwe Kleine-König (The Capable Hub)]

At module load time a platform device is registered. That should be
undone when the module is unloaded.

Fixes: ec9f47cd6a14 ("[PATCH] Serial: Split 8250 port table")
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/8250/8250.h          | 2 ++
 drivers/tty/serial/8250/8250_hub6.c     | 5 +++++
 drivers/tty/serial/8250/8250_platform.c | 5 ++++-
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 3fd25b7a7b81..f197db78c60c 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -318,8 +318,10 @@ static inline void serial8250_pnp_exit(void) { }
 
 #ifdef CONFIG_SERIAL_8250_HUB6
 int serial8250_hub6_init(void);
+void serial8250_hub6_exit(void);
 #else
 static inline int serial8250_hub6_init(void) { return 0; }
+static inline void serial8250_hub6_exit(void) { }
 #endif
 
 #ifdef CONFIG_SERIAL_8250_RSA
diff --git a/drivers/tty/serial/8250/8250_hub6.c b/drivers/tty/serial/8250/8250_hub6.c
index 3e548530ec4e..4d4c54c951cb 100644
--- a/drivers/tty/serial/8250/8250_hub6.c
+++ b/drivers/tty/serial/8250/8250_hub6.c
@@ -53,3 +53,8 @@ int __init serial8250_hub6_init(void)
 {
 	return platform_device_register(&hub6_device);
 }
+
+void __init_or_module serial8250_hub6_exit(void)
+{
+	platform_device_unregister(&hub6_device);
+}
diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c
index 3a2dff9ce7b7..0570366a71d0 100644
--- a/drivers/tty/serial/8250/8250_platform.c
+++ b/drivers/tty/serial/8250/8250_platform.c
@@ -326,7 +326,7 @@ static int __init serial8250_init(void)
 	serial8250_isa_devs = platform_device_alloc("serial8250", PLAT8250_DEV_LEGACY);
 	if (!serial8250_isa_devs) {
 		ret = -ENOMEM;
-		goto unreg_pnp;
+		goto unreg_hub6;
 	}
 
 	ret = platform_device_add(serial8250_isa_devs);
@@ -342,6 +342,8 @@ static int __init serial8250_init(void)
 	platform_device_del(serial8250_isa_devs);
 put_dev:
 	platform_device_put(serial8250_isa_devs);
+unreg_hub6:
+	serial8250_hub6_exit();
 unreg_pnp:
 	serial8250_pnp_exit();
 unreg_uart_drv:
@@ -369,6 +371,7 @@ static void __exit serial8250_exit(void)
 	platform_driver_unregister(&serial8250_isa_driver);
 	platform_device_unregister(isa_dev);
 
+	serial8250_hub6_exit();
 	serial8250_pnp_exit();
 
 #ifdef CONFIG_SPARC
-- 
2.55.0.11.g153666a7d9bb

[PATCH v3 7/7] serial: 8250: pnp: Annotate init and exit functions for conditional discarding

[Uwe Kleine-König (The Capable Hub)]

serial8250_pnp_init() is only called from serial8250_init() which is
marked with __init, so the pnp init function can also get the same
marking. serial8250_pnp_exit() is only called from __init and __exit
code, so __init_or_module is appropriate for that.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/tty/serial/8250/8250_pnp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 6bfdeff5fe22..7decf62400ab 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -526,12 +526,12 @@ static struct pnp_driver serial_pnp_driver = {
 	.id_table	= pnp_dev_table,
 };
 
-int serial8250_pnp_init(void)
+int __init serial8250_pnp_init(void)
 {
 	return pnp_register_driver(&serial_pnp_driver);
 }
 
-void serial8250_pnp_exit(void)
+void __init_or_module serial8250_pnp_exit(void)
 {
 	pnp_unregister_driver(&serial_pnp_driver);
 }
-- 
2.55.0.11.g153666a7d9bb