[PATCH v2 1/4] printk: remove BOOT_PRINTK_DELAY config option

Andrew Murray amurray at thegoodpenguin.co.uk
Tue Jun 30 09:35:57 PDT 2026


The boot_delay (BOOT_PRINTK_DELAY) kernel parameter and printk_delay sysctl
are two distinct mechanisms for providing similar functionality which add a
delay prior to each printed printk message.

In preparation of combining them into a single configurable feature, let's
first remove the kconfig option BOOT_PRINTK_DELAY.

Reviewed-by: Petr Mladek <pmladek at suse.com>
Signed-off-by: Andrew Murray <amurray at thegoodpenguin.co.uk>
---
 Documentation/admin-guide/kernel-parameters.txt |  2 +-
 arch/arm/configs/bcm2835_defconfig              |  1 -
 kernel/printk/printk.c                          |  2 +-
 lib/Kconfig.debug                               | 18 ------------------
 4 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b5493a7f8f22812833308b22f2cc35b0a42e55b2..2884103b93bca7b76cd3a93946276074cf62d0a1 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -651,7 +651,7 @@ Kernel parameters
 
 	boot_delay=	[KNL,EARLY]
 			Milliseconds to delay each printk during boot.
-			Only works if CONFIG_BOOT_PRINTK_DELAY is enabled,
+			Only works if GENERIC_CALIBRATE_DELAY is enabled,
 			and you may also have to specify "lpj=".  Boot_delay
 			values larger than 10 seconds (10000) are assumed
 			erroneous and ignored.
diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig
index 4a8ac09843d73280cc42dbbf63fe3cc9f31dacd2..51a1e94d5aa6c22202778082b877a202a6b9c04d 100644
--- a/arch/arm/configs/bcm2835_defconfig
+++ b/arch/arm/configs/bcm2835_defconfig
@@ -174,7 +174,6 @@ CONFIG_NLS_UTF8=y
 CONFIG_DMA_CMA=y
 CONFIG_CMA_SIZE_MBYTES=32
 CONFIG_PRINTK_TIME=y
-CONFIG_BOOT_PRINTK_DELAY=y
 CONFIG_DYNAMIC_DEBUG=y
 CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
 # CONFIG_ENABLE_MUST_CHECK is not set
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 2fe9a963c823a41e7df10c29939a2abb55462859..77f53eaed13216c6c3946adabc0c8fdba6401d91 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1289,7 +1289,7 @@ static bool suppress_message_printing(int level)
 	return (level >= console_loglevel && !ignore_loglevel);
 }
 
-#ifdef CONFIG_BOOT_PRINTK_DELAY
+#ifdef CONFIG_GENERIC_CALIBRATE_DELAY
 
 static int boot_delay; /* msecs delay after each printk during bootup */
 static unsigned long long loops_per_msec;	/* based on boot_delay */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1244dcac2294ad99fda37fa6767c9e76f16a4d14..b552ea51cd53b79cf5d58b8c4deff409b1982862 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -99,24 +99,6 @@ config MESSAGE_LOGLEVEL_DEFAULT
 	  by default. To change that, use loglevel=<x> in the kernel bootargs,
 	  or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
 
-config BOOT_PRINTK_DELAY
-	bool "Delay each boot printk message by N milliseconds"
-	depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
-	help
-	  This build option allows you to read kernel boot messages
-	  by inserting a short delay after each one.  The delay is
-	  specified in milliseconds on the kernel command line,
-	  using "boot_delay=N".
-
-	  It is likely that you would also need to use "lpj=M" to preset
-	  the "loops per jiffy" value.
-	  See a previous boot log for the "lpj" value to use for your
-	  system, and then set "lpj=M" before setting "boot_delay=N".
-	  NOTE:  Using this option may adversely affect SMP systems.
-	  I.e., processors other than the first one may not boot up.
-	  BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
-	  what it believes to be lockup conditions.
-
 config DYNAMIC_DEBUG
 	bool "Enable dynamic printk() support"
 	default n

-- 
2.34.1




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