[Devel] [PATCH RHEL9 COMMIT] drm: Disable modeset by default

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-362.8.1.vz9.35.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-362.8.1.vz9.35.11
------>
commit 731f0a067d1add6031855db74f66e52cb4c32a8d
Author: Konstantin Khorenko <khorenko at virtuozzo.com>
Date:   Fri Feb 9 21:02:33 2024 +0300

    drm: Disable modeset by default
    
    1. VHS and HCI are server products => nice graphical console output is not
       that important.
    2. QXL driver is buggy, we face issues with L1 VMs hungs during console writing
       using QXL driver.
    
    => let's disable framebuffer by default (like we always have "nomodeset"
    kernel boot option set).
    
    To reverse the situation, we add "modeset" kernel boot option which
    enables back framebuffer drivers usage.
    
    https://pmc.acronis.work/browse/VSTOR-81614
    
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 drivers/video/nomodeset.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/video/nomodeset.c b/drivers/video/nomodeset.c
index 13cc8b719697..1ee9c29d185b 100644
--- a/drivers/video/nomodeset.c
+++ b/drivers/video/nomodeset.c
@@ -5,7 +5,7 @@
 
 #include <video/nomodeset.h>
 
-static bool video_nomodeset;
+static bool video_nomodeset = true;
 
 bool video_firmware_drivers_only(void)
 {
@@ -22,5 +22,16 @@ static int __init disable_modeset(char *str)
 	return 1;
 }
 
+static int __init enable_modeset(char *str)
+{
+	video_nomodeset = false;
+
+	pr_warn("Booted with the modeset parameter. Full framebuffer support is enabled\n");
+
+	return 1;
+}
+
 /* Disable kernel modesetting */
 __setup("nomodeset", disable_modeset);
+/* Enable kernel modesetting */
+__setup("modeset", enable_modeset);