46cf1dacd3
This carries the text console behaviour fix as described in [1] over to the 6.12 kernel. Signed-off-by: Mathew McBride <matt@traverse.com.au> [1] https://github.com/openwrt/openwrt/pull/17012#issuecomment-2591751115 Link: https://github.com/openwrt/openwrt/pull/18849 Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
47 lines
1.8 KiB
Diff
47 lines
1.8 KiB
Diff
From 0059efbd0f9c291795078fb4e50722641d525f38 Mon Sep 17 00:00:00 2001
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From: Mathew McBride <matt@traverse.com.au>
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Date: Thu, 16 Jan 2025 11:48:44 +1100
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Subject: [PATCH] printk: always setup default (tty0 + stdout / SPCR) consoles
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when no console= present
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(This is a hack specific to OpenWrt's armsr target)
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This change resolves a difference in behaviour between arm64 ACPI
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and DT systems.
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Our usecase is to ensure the system console is always present
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regardless of display mode (serial port or screen).
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Both ACPI and DT have mechanisms to setup a serial console from
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information passed by firmware (SPCR and stdout-path respectively).
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On ACPI systems, the SPCR table is parsed very early on in the kernel
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boot which prevents the screen console (tty0) from appearing if it is
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not explicitly set.
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We would like to avoid specifying console= arguments as there are many
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possible configurations on the serial side (like ttyS0, ttyAMA0, ttymxc0
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etc.).
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If the kernel does not consume the serial port in SPCR/stdout-path,
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then the 'default' settings from the firmware (baud rate etc.) are lost.
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If the system administrator explicitly specifies a console= argument,
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then the old behaviour is returned.
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Signed-off-by: Mathew McBride <matt@traverse.com.au>
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Link: https://github.com/openwrt/openwrt/pull/17012#issuecomment-2591751115
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---
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kernel/printk/printk.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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--- a/kernel/printk/printk.c
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+++ b/kernel/printk/printk.c
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@@ -3978,7 +3978,7 @@ void register_console(struct console *ne
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* Note that a console with tty binding will have CON_CONSDEV
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* flag set and will be first in the list.
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*/
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- if (preferred_console < 0) {
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+ if (!console_set_on_cmdline) {
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if (hlist_empty(&console_list) || !console_first()->device ||
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console_first()->flags & CON_BOOT) {
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try_enable_default_console(newcon);
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