[PATCH] docs: sysctl/kernel: document acpi_video_flags

[Stephen Kitt]

Based on the implementation in arch/x86/kernel/acpi/sleep.c, in
particular the acpi_sleep_setup() function.

Signed-off-by: Stephen Kitt <steve@xxxxxxx>
---
 Documentation/admin-guide/sysctl/kernel.rst | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 534781ba3eac..1c48ab4bfe30 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -54,8 +54,15 @@ free space valid for 30 seconds.
 acpi_video_flags
 ================
 
-See Documentation/kernel/power/video.txt, it allows mode of video boot
-to be set during run time.
+See :doc:`/power/video`. This allows the video resume mode to be set,
+in a similar fashion to the ``acpi_sleep`` kernel parameter, by
+combining the following values:
+
+= =======
+1 s3_bios
+2 s3_mode
+4 s3_beep
+= =======
 
 
 auto_msgmni
-- 
2.20.1