* [PATCH v1 0/6] serial: Some yak shaving
@ 2026-07-31 9:39 Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 1/6] serial: txx9: Drop noop probe function and dangerous remove callback Uwe Kleine-König
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby, Hugo Villeneuve
Cc: John Ogness, Atsushi Nemoto, Alan Cox, linux-kernel, linux-serial,
Jonathan Corbet, Shuah Khan, Stepan Ionichev, Fushuai Wang,
Osama Abdelkader, linux-doc, Ilpo Järvinen, Andy Shevchenko,
Abinash Singh, Kees Cook, Gerhard Engleder, Lukas Wunner,
Huacai Chen, Binbin Zhou, Rong Zhang, Randy Dunlap, Haowei Zheng,
Rahul Bukte, Russell King
Hello,
after the discussion with Hugo about hub6_match_port()[1] I looked into
implementing my suggestion. Hugo had a doubt there:
> I am not sure to fully understand what you suggest. Copying the same
> function code to two drivers seems like a waisted opportunity for code
> reuse?
I don't think this is a wasted opportunity, as uart_match_port() only
becomes a single comparison for the txx9 driver. Also having 8250
specific parts in serial_core is a layer violation.
I was unable to unsee some of the stuff I discovered, so there are a few
more patches in this series now ...
The first txx9 patch is a preparation for the second to establish the
assertion ".iotype is always UPIO_PORT". It's also a fix that is correct
on its own (assuming I understood the driver model misuse in this driver
correctly).
After that uart_match_port() is only used by the 8250 driver code and
thus can be moved to there in the third patch, simplifying the
dependencies a bit which enables fixing the breakage I found in the
fourth patch.
The two remaining patches are cleanups I found while working on that
driver.
Note this is only compile tested as I don't have a machine with any of
the three affected serial hardwares.
Best regards
Uwe
[1] https://lore.kernel.org/linux-serial/amn8Hb2dbv_Sah_Y@monoceros/
Uwe Kleine-König (6):
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: 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 | 27 +++++++++-
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 | 57 ++--------------------
include/linux/serial_core.h | 2 -
11 files changed, 58 insertions(+), 97 deletions(-)
base-commit: 95d6a9ccef99117115e41e9adb271243bd5e985b
--
2.55.0.11.g153666a7d9bb
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v1 1/6] serial: txx9: Drop noop probe function and dangerous remove callback
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 2/6] serial: txx9: Drop usage of uart_match_port() Uwe Kleine-König
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Hugo Villeneuve, John Ogness, Atsushi Nemoto, Alan Cox,
linux-kernel, linux-serial
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")
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
---
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..5ed20129b44b 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 (up->iobase || up->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
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v1 2/6] serial: txx9: Drop usage of uart_match_port()
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 1/6] serial: txx9: Drop noop probe function and dangerous remove callback Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 3/6] serial: 8250: Make uart_match_port() a 8250 specific function Uwe Kleine-König
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Hugo Villeneuve, John Ogness, linux-kernel, linux-serial
In this driver .iotype is always 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 <ukleinek@kernel.org>
---
drivers/tty/serial/serial_txx9.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index 5ed20129b44b..2368081c3742 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -965,7 +965,7 @@ 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)) {
+ if (uart->iobase == port->iobase)
uart_remove_one_port(&serial_txx9_reg, uart);
break;
}
--
2.55.0.11.g153666a7d9bb
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v1 3/6] serial: 8250: Make uart_match_port() a 8250 specific function
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 1/6] serial: txx9: Drop noop probe function and dangerous remove callback Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 2/6] serial: txx9: Drop usage of uart_match_port() Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 4/6] serial: 8250: Fix corner case for port matching Uwe Kleine-König
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Jonathan Corbet, Shuah Khan, John Ogness, Stepan Ionichev,
Fushuai Wang, Osama Abdelkader, Hugo Villeneuve, linux-kernel,
linux-serial, linux-doc
The 8250 driver conglomerate is the only user of this function 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.
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
---
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 c0e8a4efbdcc..6059b84d8364 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -630,6 +630,31 @@ 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;
@@ -638,7 +663,7 @@ 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 edd1e7be2a5c..8a6c53a9996e 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.
@@ -3229,32 +3228,6 @@ 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 c4cc4f66af4b..1659805e2233 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -1137,8 +1137,6 @@ 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
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v1 4/6] serial: 8250: Fix corner case for port matching
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
` (2 preceding siblings ...)
2026-07-31 9:39 ` [PATCH v1 3/6] serial: 8250: Make uart_match_port() a 8250 specific function Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 5/6] serial: 8250: hub6: Add cleanup code Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 6/6] serial: 8250: pnp: Annotate init and exit functions for conditional discarding Uwe Kleine-König
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Ilpo Järvinen, Andy Shevchenko, Hugo Villeneuve,
Abinash Singh, Kees Cook, Gerhard Engleder, Lukas Wunner,
Huacai Chen, Binbin Zhou, Rong Zhang, Randy Dunlap, Haowei Zheng,
linux-kernel, linux-serial
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")
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
---
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 b62f88eec881..39d72f1480c0 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -315,6 +315,12 @@ 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);
@@ -335,7 +341,7 @@ 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 5a0bc1fae11d..e8524d545de9 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 fc3e58d62233..00c2ced12717 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -294,8 +294,8 @@ 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 6d21402b4435..416c32e3aba2 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
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v1 5/6] serial: 8250: hub6: Add cleanup code
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
` (3 preceding siblings ...)
2026-07-31 9:39 ` [PATCH v1 4/6] serial: 8250: Fix corner case for port matching Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 6/6] serial: 8250: pnp: Annotate init and exit functions for conditional discarding Uwe Kleine-König
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Hugo Villeneuve, Andy Shevchenko, Ilpo Järvinen,
Abinash Singh, Rahul Bukte, Kees Cook, Russell King, linux-kernel,
linux-serial
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")
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
---
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 39d72f1480c0..01fed8d44b7b 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -317,8 +317,10 @@ 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..55320b794165 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);
}
+
+int __init_or_module serial8250_hub6_exit(void)
+{
+ return platform_device_unregister(&hub6_device);
+}
diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c
index e8524d545de9..72076ccb5bde 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
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v1 6/6] serial: 8250: pnp: Annotate init and exit functions for conditional discarding
2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
` (4 preceding siblings ...)
2026-07-31 9:39 ` [PATCH v1 5/6] serial: 8250: hub6: Add cleanup code Uwe Kleine-König
@ 2026-07-31 9:39 ` Uwe Kleine-König
5 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-07-31 9:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Hugo Villeneuve, Rahul Bukte, linux-kernel, linux-serial
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.
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
---
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 b39f005f11cf..e142f4296062 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
^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2026-07-31 9:39 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2026-07-31 9:39 [PATCH v1 0/6] serial: Some yak shaving Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 1/6] serial: txx9: Drop noop probe function and dangerous remove callback Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 2/6] serial: txx9: Drop usage of uart_match_port() Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 3/6] serial: 8250: Make uart_match_port() a 8250 specific function Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 4/6] serial: 8250: Fix corner case for port matching Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 5/6] serial: 8250: hub6: Add cleanup code Uwe Kleine-König
2026-07-31 9:39 ` [PATCH v1 6/6] serial: 8250: pnp: Annotate init and exit functions for conditional discarding Uwe Kleine-König
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