drm/fb_helper: Disable all crtc's when initial setup fails.

commit 52dd065 upstream. Some drivers like i915 start with crtc's enabled, but with deferred fbcon setup they were no longer disabled as part of fbdev setup. Headless units could no longer enter pc3 state because the crtc was still enabled. Fix this by calling restore_fbdev_mode when we would have called it otherwise once during initial fbdev setup. Signed-off-by: Maarten Lankhorst <[email protected]> Fixes: ca91a27 ("drm/fb-helper: Support deferred setup") Reported-by: Thomas Voegtle <[email protected]> Tested-by: Thomas Voegtle <[email protected]> Reviewed-by: Daniel Vetter <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
maraz · Dec 5, 2017 · dde499d · dde499d
1 parent e4c84b5
commit dde499d
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
@@ -1809,6 +1809,10 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 
 	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
 		DRM_INFO("Cannot find any crtc or sizes\n");
+
+		/* First time: disable all crtc's.. */
+		if (!fb_helper->deferred_setup && !READ_ONCE(fb_helper->dev->master))
+			restore_fbdev_mode(fb_helper);
 		return -EAGAIN;
 	}