1 files changed, 96 insertions, 0 deletions
diff --git a/queue-6.6/dummycon-trigger-redraw-when-switching-consoles-with.patch b/queue-6.6/dummycon-trigger-redraw-when-switching-consoles-with.patch
new file mode 100644
index 0000000000..e69f079337
--- /dev/null
+++ b/queue-6.6/dummycon-trigger-redraw-when-switching-consoles-with.patch
@@ -0,0 +1,96 @@
+From 84154bf81a79be1af1789dbe8f5da7daea52843a Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Tue, 20 May 2025 09:14:00 +0200
+Subject: dummycon: Trigger redraw when switching consoles with deferred
+ takeover
+
+From: Thomas Zimmermann <tzimmermann@suse.de>
+
+[ Upstream commit 03bcbbb3995ba5df43af9aba45334e35f2dfe27b ]
+
+Signal vt subsystem to redraw console when switching to dummycon
+with deferred takeover enabled. Makes the console switch to fbcon
+and displays the available output.
+
+With deferred takeover enabled, dummycon acts as the placeholder
+until the first output to the console happens. At that point, fbcon
+takes over. If the output happens while dummycon is not active, it
+cannot inform fbcon. This is the case if the vt subsystem runs in
+graphics mode.
+
+A typical graphical boot starts plymouth, a display manager and a
+compositor; all while leaving out dummycon. Switching to a text-mode
+console leaves the console with dummycon even if a getty terminal
+has been started.
+
+Returning true from dummycon's con_switch helper signals the vt
+subsystem to redraw the screen. If there's output available dummycon's
+con_putc{s} helpers trigger deferred takeover of fbcon, which sets a
+display mode and displays the output. If no output is available,
+dummycon remains active.
+
+v2:
+- make the comment slightly more verbose (Javier)
+
+Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
+Reported-by: Andrei Borzenkov <arvidjaar@gmail.com>
+Closes: https://bugzilla.suse.com/show_bug.cgi?id=1242191
+Tested-by: Andrei Borzenkov <arvidjaar@gmail.com>
+Acked-by: Javier Martinez Canillas <javierm@redhat.com>
+Fixes: 83d83bebf401 ("console/fbcon: Add support for deferred console takeover")
+Cc: Hans de Goede <hdegoede@redhat.com>
+Cc: linux-fbdev@vger.kernel.org
+Cc: dri-devel@lists.freedesktop.org
+Cc: <stable@vger.kernel.org> # v4.19+
+Link: https://lore.kernel.org/r/20250520071418.8462-1-tzimmermann@suse.de
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/video/console/dummycon.c | 18 +++++++++++++-----
+ 1 file changed, 13 insertions(+), 5 deletions(-)
+
+diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
+index d701f2b51f5b1..d99e1b3e4e5c1 100644
+--- a/drivers/video/console/dummycon.c
++++ b/drivers/video/console/dummycon.c
+@@ -82,6 +82,15 @@ static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
+ 	/* Redraw, so that we get putc(s) for output done while blanked */
+ 	return 1;
+ }
++
++static bool dummycon_switch(struct vc_data *vc)
++{
++	/*
++	 * Redraw, so that we get putc(s) for output done while switched
++	 * away. Informs deferred consoles to take over the display.
++	 */
++	return true;
++}
+ #else
+ static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
+ static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
+@@ -90,6 +99,10 @@ static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
+ {
+ 	return 0;
+ }
++static bool dummycon_switch(struct vc_data *vc)
++{
++	return false;
++}
+ #endif
+ 
+ static const char *dummycon_startup(void)
+@@ -119,11 +132,6 @@ static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
+ 	return false;
+ }
+ 
+-static bool dummycon_switch(struct vc_data *vc)
+-{
+-	return false;
+-}
+-
+ /*
+  *  The console `switch' structure for the dummy console
+  *
+-- 
+2.39.5
+