video/aperture: Disable and unregister sysfb devices via aperture helpers

Call sysfb_disable() before removing conflicting devices in aperture
helpers. Fixes sysfb state if fbdev has been disabled.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: fb84efa2 ("drm/aperture: Run fbdev removal before internal helpers")
Cc: Zack Rusin <zackr@vmware.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Changcheng Deng <deng.changcheng@zte.com.cn>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220718072322.8927-8-tzimmermann@suse.de

drivers/video/aperture.c

@@ -8,6 +8,7 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/sysfb.h>
 #include <linux/types.h>
 #include <linux/vgaarb.h>
 
@@ -286,7 +287,20 @@ int aperture_remove_conflicting_devices(resource_size_t base, resource_size_t si
 #if IS_REACHABLE(CONFIG_FB)
 	struct apertures_struct *a;
 	int ret;
+#endif
+
+	/*
+	 * If a driver asked to unregister a platform device registered by
+	 * sysfb, then can be assumed that this is a driver for a display
+	 * that is set up by the system firmware and has a generic driver.
+	 *
+	 * Drivers for devices that don't have a generic driver will never
+	 * ask for this, so let's assume that a real driver for the display
+	 * was already probed and prevent sysfb to register devices later.
+	 */
+	sysfb_disable();
 
+#if IS_REACHABLE(CONFIG_FB)
 	a = alloc_apertures(1);
 	if (!a)
 		return -ENOMEM;

drivers/video/fbdev/core/fbmem.c

@@ -19,7 +19,6 @@
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/slab.h>
-#include <linux/sysfb.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/vt.h>
@@ -1777,17 +1776,6 @@ int remove_conflicting_framebuffers(struct apertures_struct *a,
 		do_free = true;
 	}
 
-	/*
-	 * If a driver asked to unregister a platform device registered by
-	 * sysfb, then can be assumed that this is a driver for a display
-	 * that is set up by the system firmware and has a generic driver.
-	 *
-	 * Drivers for devices that don't have a generic driver will never
-	 * ask for this, so let's assume that a real driver for the display
-	 * was already probed and prevent sysfb to register devices later.
-	 */
-	sysfb_disable();
-
 	mutex_lock(&registration_lock);
 	do_remove_conflicting_framebuffers(a, name, primary);
 	mutex_unlock(&registration_lock);