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 ---

Dave: It would be nice if I could merge this patch through bcm2835-dt-next, where I'm trying to get the VC4 DT merged even though the defconfig includes both VC4 and simplefb. There aren't any conflicts with anything I'm merging through drm-next.

drivers/gpu/drm/vc4/vc4_drv.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index b7d2ff0e6e1f..109b10651959 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -153,6 +153,24 @@ static void vc4_match_add_drivers(struct device *dev, } }

+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); @@ -186,6 +204,8 @@ static int vc4_drm_bind(struct device *dev) if (ret) goto gem_destroy;

+ vc4_kick_out_firmware_fb(); + ret = drm_dev_register(drm, 0); if (ret < 0) goto unbind_all;