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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-05-11 16:52:50 +0200
committerMaxime Ripard <maxime.ripard@free-electrons.com>2016-05-30 08:28:33 +0200
commit3d6bd9065b7acf8499d414d70bdb4b4955856299 (patch)
tree0d39cf983139987da13d087926410fe437cf4480
parent0de6e914a035076b1241f5738c06c9d3820abd6e (diff)
drm/sun4i: remove simplefb at probe
If simplefb was setup by our bootloader and enabled in the DT, we will have a first framebuffer loaded in our system. However, as soon as our DRM driver will load, it will reset the controller, initialise it and, if the framebuffer emulation is enabled, register a second framebuffer device. This is obviously pretty bad, since the first framebuffer will be some kind of a black hole, with memory still reserved that we can write to safely, but not displayed anywhere. Make sure we remove that framebuffer when we probe so we don't end up in that situation. Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
-rw-r--r--drivers/gpu/drm/sun4i/sun4i_drv.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 76e922b..af62b24 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -125,6 +125,22 @@ static struct drm_driver sun4i_drv_driver = {
.disable_vblank = sun4i_drv_disable_vblank,
};
+static void sun4i_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;
+
+ remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
+ kfree(ap);
+}
+
static int sun4i_drv_bind(struct device *dev)
{
struct drm_device *drm;
@@ -172,6 +188,9 @@ static int sun4i_drv_bind(struct device *dev)
}
drm->irq_enabled = true;
+ /* Remove early framebuffers (ie. simplefb) */
+ sun4i_remove_framebuffers();
+
/* Create our framebuffer */
drv->fbdev = sun4i_framebuffer_init(drm);
if (IS_ERR(drv->fbdev)) {