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[v1,1/1] serial: 8250_platform: Explicitly show we initialise ISA ports only once

Message ID 20240606184841.3102545-1-andriy.shevchenko@linux.intel.com
State New
Headers show
Series [v1,1/1] serial: 8250_platform: Explicitly show we initialise ISA ports only once | expand

Commit Message

Andy Shevchenko June 6, 2024, 6:48 p.m. UTC
serial8250_isa_init_ports() uses home grown approach to make itself
a singleton. Instead, explicitly show that we initialise ISA ports
once by providing a helper function which calls the original function
via DO_ONCE() macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 drivers/tty/serial/8250/8250_platform.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)


kernel test robot June 7, 2024, 1:48 p.m. UTC | #1
Hi Andy,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tty/tty-testing]
[also build test WARNING on tty/tty-next next-20240607]
[cannot apply to tty/tty-linus linus/master v6.10-rc2]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/serial-8250_platform-Explicitly-show-we-initialise-ISA-ports-only-once/20240607-025109
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
patch link:    https://lore.kernel.org/r/20240606184841.3102545-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v1 1/1] serial: 8250_platform: Explicitly show we initialise ISA ports only once
config: loongarch-defconfig (https://download.01.org/0day-ci/archive/20240607/202406072102.SGp8FYYi-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240607/202406072102.SGp8FYYi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202406072102.SGp8FYYi-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/tty/serial/8250/8250_platform.o: warning: objtool: __jump_table+0x0: special: can't find orig instruction

objdump-func vmlinux.o __jump_table:
diff mbox series


diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c
index ded985182e04..5817c1d72314 100644
--- a/drivers/tty/serial/8250/8250_platform.c
+++ b/drivers/tty/serial/8250/8250_platform.c
@@ -9,6 +9,7 @@ 
 #include <linux/array_size.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/once.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
@@ -53,15 +54,10 @@  void serial8250_set_isa_configurator(serial8250_isa_config_fn v)
-void __init serial8250_isa_init_ports(void)
+static void __init __serial8250_isa_init_ports(void)
-	static int first = 1;
 	int i, irqflag = 0;
-	if (!first)
-		return;
-	first = 0;
 	if (nr_uarts > UART_NR)
 		nr_uarts = UART_NR;
@@ -102,6 +98,11 @@  void __init serial8250_isa_init_ports(void)
+void __init serial8250_isa_init_ports(void)
+	DO_ONCE(__serial8250_isa_init_ports);
  * Register a set of serial devices attached to a platform device.  The
  * list is terminated with a zero flags entry, which means we expect