[PATCH] drm/rockchip: kick firmware-based framebuffer when initializing

Since U-Boot now supports EFI and FB passing via EFI GOP, when booting
rockchip SoCs via EFI, a EFI FB is available. However, currently when
re-initializing display pipeline, the EFI FB is not removed, lead to
fbcon not working (because the EFI FB is no longer bound to the display
pipeline although it's still /dev/fb0 and fbcon is bound to it).

Add some code for removing firmware-based FB when initializing KMS of
rockchipdrm.

Tested on Pinebook Pro (RK3399) with U-Boot patchset for initializing
eDP display applied.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
  drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index 212bd87c0c4a..3905fce6ce0b 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -158,6 +158,9 @@ static int rockchip_drm_bind(struct device *dev)
  	 */
  	drm_dev->irq_enabled = true;
  
+	/* Remove early framebuffers (ie. efifb) */
+	drm_fb_helper_remove_conflicting_framebuffers(NULL, "rockchipdrmfb", false);
+
  	ret = rockchip_drm_fbdev_init(drm_dev);
  	if (ret)
  		goto err_unbind_all;