Commit 1a336c93 authored by Manuel Schölling's avatar Manuel Schölling Committed by Greg Kroah-Hartman

console: Make persistent scrollback a boot parameter

The impact of the persistent scrollback feature on the code size is
rather small, so the config option is removed. The feature stays
disabled by default and can be enabled by using the boot command line
parameter 'vgacon.scrollback_persistent=1' or by setting
VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT=y.
Signed-off-by: default avatarManuel Schölling <manuel.schoelling@gmx.de>
Suggested-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aabd31c4
...@@ -47,14 +47,16 @@ config VGACON_SOFT_SCROLLBACK_SIZE ...@@ -47,14 +47,16 @@ config VGACON_SOFT_SCROLLBACK_SIZE
buffers of VGA consoles. Each 64KB will give you approximately buffers of VGA consoles. Each 64KB will give you approximately
16 80x25 screenfuls of scrollback buffer. 16 80x25 screenfuls of scrollback buffer.
config VGACON_SOFT_SCROLLBACK_PERSISTENT config VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT
bool "Persistent Scrollback History for each console" bool "Persistent Scrollback History for each console by default"
depends on VGACON_SOFT_SCROLLBACK depends on VGACON_SOFT_SCROLLBACK
default n default n
help help
Say Y here if the scrollback history should persist when switching Say Y here if the scrollback history should persist by default when
between consoles. Otherwise, the scrollback history will be flushed switching between consoles. Otherwise, the scrollback history will be
each time the console is switched. flushed each time the console is switched. This feature can also be
enabled using the boot command line parameter
'vgacon.scrollback_persistent=1'.
This feature might break your tool of choice to flush the scrollback This feature might break your tool of choice to flush the scrollback
buffer, e.g. clear(1) will work fine but Debian's clear_console(1) buffer, e.g. clear(1) will work fine but Debian's clear_console(1)
......
...@@ -174,11 +174,11 @@ struct vgacon_scrollback_info { ...@@ -174,11 +174,11 @@ struct vgacon_scrollback_info {
}; };
static struct vgacon_scrollback_info *vgacon_scrollback_cur; static struct vgacon_scrollback_info *vgacon_scrollback_cur;
#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES]; static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES];
#else static bool scrollback_persistent = \
static struct vgacon_scrollback_info vgacon_scrollbacks[1]; IS_ENABLED(CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT);
#endif module_param_named(scrollback_persistent, scrollback_persistent, bool, 0000);
MODULE_PARM_DESC(scrollback_persistent, "Enable persistent scrollback for all vga consoles");
static void vgacon_scrollback_reset(int vc_num, size_t reset_size) static void vgacon_scrollback_reset(int vc_num, size_t reset_size)
{ {
...@@ -213,20 +213,19 @@ static void vgacon_scrollback_init(int vc_num) ...@@ -213,20 +213,19 @@ static void vgacon_scrollback_init(int vc_num)
static void vgacon_scrollback_switch(int vc_num) static void vgacon_scrollback_switch(int vc_num)
{ {
#ifndef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT if (!scrollback_persistent)
vc_num = 0; vc_num = 0;
#endif
if (!vgacon_scrollbacks[vc_num].data) { if (!vgacon_scrollbacks[vc_num].data) {
vgacon_scrollback_init(vc_num); vgacon_scrollback_init(vc_num);
} else { } else {
#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT if (scrollback_persistent) {
vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num]; vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
#else } else {
size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024; size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
vgacon_scrollback_reset(vc_num, size); vgacon_scrollback_reset(vc_num, size);
#endif }
} }
} }
......
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