redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

acpi/x86: add a kernel parameter to disable ACPI BGRT

Browse source 
BGRT is for displaying seamless OEM logo from booting to login screen;
however, this mechanism does not always work well on all configurations
and the OEM logo can be displayed multiple times. This looks worse than
without BGRT enabled.

This patch adds a kernel parameter to disable BGRT in boot time. This is
easier than re-compiling a kernel with CONFIG_ACPI_BGRT disabled.

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Alex Hung 2020-03-04 15:55:29 -07:00 committed by Rafael J. Wysocki
parent fa0fca68e1
commit 1ffb8d032d
2 changed files with 12 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
Documentation/admin-guide/kernel-parameters.txt
View file

@ -450,6 +450,9 @@
bert_disable [ACPI]
Disable BERT OS support on buggy BIOSes.
bgrt_disable [ACPI][X86]
Disable BGRT to avoid flickering OEM logo.
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.

10
arch/x86/kernel/acpi/boot.c
View file

@ -45,6 +45,7 @@ EXPORT_SYMBOL(acpi_disabled);
#define PREFIX "ACPI: "
int acpi_noirq; /* skip ACPI IRQ initialization */
int acpi_nobgrt; /* skip ACPI BGRT */
int acpi_pci_disabled; /* skip ACPI PCI scan and IRQ initialization */
EXPORT_SYMBOL(acpi_pci_disabled);
@ -1619,7 +1620,7 @@ int __init acpi_boot_init(void)
acpi_process_madt();
acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
if (IS_ENABLED(CONFIG_ACPI_BGRT))
if (IS_ENABLED(CONFIG_ACPI_BGRT) && !acpi_nobgrt)
acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
if (!acpi_noirq)
@ -1671,6 +1672,13 @@ static int __init parse_acpi(char *arg)
}
early_param("acpi", parse_acpi);
static int __init parse_acpi_bgrt(char *arg)
{
acpi_nobgrt = true;
return 0;
}
early_param("bgrt_disable", parse_acpi_bgrt);
/* FIXME: Using pci= for an ACPI parameter is a travesty. */
static int __init parse_pci(char *arg)
{