drm/meson: remove firmware framebuffers

In case we are using simplefb or another conflicting framebuffer, make
the call to drm_fb_helper_remove_conflicting_framebuffers()
Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181210092853.13050-1-mjourdan@baylibre.com

drivers/gpu/drm/meson/meson_drv.c

@@ -152,6 +152,23 @@ static void meson_vpu_init(struct meson_drm *priv)
 	writel_relaxed(0x20000, priv->io_base + _REG(VPU_WRARB_MODE_L2C1));
 }
 
+static void meson_remove_framebuffers(void)
+{
+	struct apertures_struct *ap;
+
+	ap = alloc_apertures(1);
+	if (!ap)
+		return;
+
+	/* The framebuffer can be located anywhere in RAM */
+	ap->ranges[0].base = 0;
+	ap->ranges[0].size = ~0;
+
+	drm_fb_helper_remove_conflicting_framebuffers(ap, "meson-drm-fb",
+						      false);
+	kfree(ap);
+}
+
 static int meson_drv_bind_master(struct device *dev, bool has_components)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -262,6 +279,9 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	if (ret)
 		goto free_drm;
 
+	/* Remove early framebuffers (ie. simplefb) */
+	meson_remove_framebuffers();
+
 	drm_mode_config_init(drm);
 	drm->mode_config.max_width = 3840;
 	drm->mode_config.max_height = 2160;