openwrtv3/target/linux/brcm2708/patches-4.4/0333-drm-vc4-Kick-out-the-simplefb-framebuffer-before-we-.patch

From 36e64f18d0df45797656ddbbcf6a58cfae397ca1 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 19 Apr 2016 13:24:14 -0700
Subject: [PATCH] drm/vc4: Kick out the simplefb framebuffer before we set up
 KMS.

If we don't, then simplefb stays loaded on /dev/fb0 even though
scanout isn't happening from simplefb's memory area any more, and you
end up with no console.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit b3a15f6d55fb584dd4d8baac5d1b6a398720620c)
---
 drivers/gpu/drm/vc4/vc4_drv.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -164,6 +164,24 @@ static void vc4_match_add_drivers(struct
 	}
 }
 
+static void vc4_kick_out_firmware_fb(void)
+{
+	struct apertures_struct *ap;
+
+	ap = alloc_apertures(1);
+	if (!ap)
+		return;
+
+	/* Since VC4 is a UMA device, the simplefb node may have been
+	 * located anywhere in memory.
+	 */
+	ap->ranges[0].base = 0;
+	ap->ranges[0].size = ~0;
+
+	remove_conflicting_framebuffers(ap, "vc4drmfb", false);
+	kfree(ap);
+}
+
 static int vc4_drm_bind(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -208,6 +226,8 @@ static int vc4_drm_bind(struct device *d
 	if (ret)
 		goto gem_destroy;
 
+	vc4_kick_out_firmware_fb();
+
 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)
 		goto unbind_all;