Patch "drm/mgag200: Fix value in <VBLKSTR> register" has been added to the 6.14-stable tree

Patch "drm/mgag200: Fix value in <VBLKSTR> register" has been added to the 6.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/mgag200: Fix value in <VBLKSTR> register

to the 6.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-mgag200-fix-value-in-vblkstr-register.patch
and it can be found in the queue-6.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From 76c332d119f9048c6e16b52359f401510f18b2ff Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 16 Apr 2025 10:38:05 +0200
Subject: drm/mgag200: Fix value in <VBLKSTR> register
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Thomas Zimmermann <tzimmermann@suse.de>

commit 76c332d119f9048c6e16b52359f401510f18b2ff upstream.

Fix an off-by-one error when setting the vblanking start in
<VBLKSTR>. Commit d6460bd52c27 ("drm/mgag200: Add dedicated
variables for blanking fields") switched the value from
crtc_vdisplay to crtc_vblank_start, which DRM helpers copy
from the former. The commit missed to subtract one though.

Reported-by: Wakko Warner <wakko@animx.eu.org>
Closes: https://lore.kernel.org/dri-devel/CAMwc25rKPKooaSp85zDq2eh-9q4UPZD=RqSDBRp1fAagDnmRmA@mail.gmail.com/
Reported-by: Сергей <afmerlord@gmail.com>
Closes: https://lore.kernel.org/all/5b193b75-40b1-4342-a16a-ae9fc62f245a@gmail.com/
Closes: https://bbs.archlinux.org/viewtopic.php?id=303819
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d6460bd52c27 ("drm/mgag200: Add dedicated variables for blanking fields")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.12+
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Wakko Warner <wakko@animx.eu.org>
Link: https://lore.kernel.org/r/20250416083847.51764-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/mgag200/mgag200_mode.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -223,7 +223,7 @@ void mgag200_set_mode_regs(struct mga_de
 	vsyncstr = mode->crtc_vsync_start - 1;
 	vsyncend = mode->crtc_vsync_end - 1;
 	vtotal = mode->crtc_vtotal - 2;
-	vblkstr = mode->crtc_vblank_start;
+	vblkstr = mode->crtc_vblank_start - 1;
 	vblkend = vtotal + 1;
 
 	linecomp = vdispend;


Patches currently in stable-queue which might be from tzimmermann@suse.de are

queue-6.14/drm-mgag200-fix-value-in-vblkstr-register.patch
queue-6.14/drm-ast-fix-ast_dp-connection-status.patch