Patch "drm/vmwgfx: Trigger a modeset when the screen moves" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    drm/vmwgfx: Trigger a modeset when the screen moves

to the 6.6-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-vmwgfx-trigger-a-modeset-when-the-screen-moves.patch
and it can be found in the queue-6.6 subdirectory.

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



commit 79b413d8535d8d568136e545f8883eeddcacd5f8
Author: Ian Forbes <ian.forbes@xxxxxxxxxxxx>
Date:   Mon Jun 24 15:59:51 2024 -0500

    drm/vmwgfx: Trigger a modeset when the screen moves
    
    [ Upstream commit 75c3e8a26a35d4f3eee299b3cc7e465f166f4e2d ]
    
    When multi-monitor is cycled the X,Y position of the Screen Target will
    likely change but the resolution will not. We need to trigger a modeset
    when this occurs in order to recreate the Screen Target with the correct
    X,Y position.
    
    Fixes a bug where multiple displays are shown in a single scrollable
    host window rather than in 2+ windows on separate host displays.
    
    Fixes: 426826933109 ("drm/vmwgfx: Filter modes which exceed graphics memory")
    Signed-off-by: Ian Forbes <ian.forbes@xxxxxxxxxxxx>
    Signed-off-by: Zack Rusin <zack.rusin@xxxxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20240624205951.23343-1-ian.forbes@xxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
index 4ccab07faff08..cb03c589ab226 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -868,6 +868,32 @@ vmw_stdu_connector_mode_valid(struct drm_connector *connector,
 	return MODE_OK;
 }
 
+/*
+ * Trigger a modeset if the X,Y position of the Screen Target changes.
+ * This is needed when multi-mon is cycled. The original Screen Target will have
+ * the same mode but its relative X,Y position in the topology will change.
+ */
+static int vmw_stdu_connector_atomic_check(struct drm_connector *conn,
+					   struct drm_atomic_state *state)
+{
+	struct drm_connector_state *conn_state;
+	struct vmw_screen_target_display_unit *du;
+	struct drm_crtc_state *new_crtc_state;
+
+	conn_state = drm_atomic_get_connector_state(state, conn);
+	du = vmw_connector_to_stdu(conn);
+
+	if (!conn_state->crtc)
+		return 0;
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
+	if (du->base.gui_x != du->base.set_gui_x ||
+	    du->base.gui_y != du->base.set_gui_y)
+		new_crtc_state->mode_changed = true;
+
+	return 0;
+}
+
 static const struct drm_connector_funcs vmw_stdu_connector_funcs = {
 	.dpms = vmw_du_connector_dpms,
 	.detect = vmw_du_connector_detect,
@@ -882,7 +908,8 @@ static const struct drm_connector_funcs vmw_stdu_connector_funcs = {
 static const struct
 drm_connector_helper_funcs vmw_stdu_connector_helper_funcs = {
 	.get_modes = vmw_connector_get_modes,
-	.mode_valid = vmw_stdu_connector_mode_valid
+	.mode_valid = vmw_stdu_connector_mode_valid,
+	.atomic_check = vmw_stdu_connector_atomic_check,
 };