From: Alex Hung <alex.hung@canonical.com>
To: corbet@lwn.net, rjw@rjwysocki.net, len.brown@intel.com,
pavel@ucw.cz, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, x86@kernel.org, mchehab+samsung@kernel.org,
jpoimboe@redhat.com, akpm@linux-foundation.org,
pawan.kumar.gupta@linux.intel.com, jgross@suse.com,
linux-doc@vger.kernel.org, linux-pm@vger.kernel.org,
linux-acpi@vger.kernel.org, alex.hung@canonical.com
Subject: [PATCH][RESEND] acpi/x86: add a kernel parameter to disable ACPI BGRT
Date: Wed, 4 Mar 2020 15:55:29 -0700 [thread overview]
Message-ID: <20200304225529.6706-1-alex.hung@canonical.com> (raw)
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>
---
* Resend to include linux-acpi emailing list
Documentation/admin-guide/kernel-parameters.txt | 3 +++
arch/x86/kernel/acpi/boot.c | 10 +++++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index ffff776..55c5b2f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -442,6 +442,9 @@
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.
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 04205ce..d1757ce 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -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)
{
--
2.7.4
next reply other threads:[~2020-03-04 22:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 22:55 Alex Hung [this message]
2020-03-14 9:38 ` [PATCH][RESEND] acpi/x86: add a kernel parameter to disable ACPI BGRT Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200304225529.6706-1-alex.hung@canonical.com \
--to=alex.hung@canonical.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=corbet@lwn.net \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=jpoimboe@redhat.com \
--cc=len.brown@intel.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mchehab+samsung@kernel.org \
--cc=mingo@redhat.com \
--cc=pavel@ucw.cz \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=rjw@rjwysocki.net \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).