drm/gma500: Remove generic DRM drivers in probe function

Gma500 currently removes generic fbdev drivers, but ignores
generic DRM drivers. Use aperture helpers to remove all generic
graphics drivers before loading gma500. Makes gma500 compatible
with simpledrm.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211019080942.24356-1-tzimmermann@suse.de

drivers/gpu/drm/gma500/psb_drv.c

@@ -19,6 +19,7 @@
 #include <acpi/video.h>
 
 #include <drm/drm.h>
+#include <drm/drm_aperture.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_file.h>
@@ -448,6 +449,17 @@ static int psb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct drm_device *dev;
 	int ret;
 
+	/*
+	 * We cannot yet easily find the framebuffer's location in memory. So
+	 * remove all framebuffers here.
+	 *
+	 * TODO: Refactor psb_driver_load() to map vdc_reg earlier. Then we
+	 *       might be able to read the framebuffer range from the device.
+	 */
+	ret = drm_aperture_remove_framebuffers(true, &driver);
+	if (ret)
+		return ret;
+
 	ret = pcim_enable_device(pdev);
 	if (ret)
 		return ret;