I am working on getting HDMI output enabled in mainline Linux for our RK3399-Q7 module. It works fine on v4.16, but testing with v4.17-rc2 I get this, and the screen stays black: > [ 7.142712] alloc_contig_range: [7f061, 7f062) PFNs busy > [ 7.148862] alloc_contig_range: [7f066, 7f067) PFNs busy > [ 7.155041] alloc_contig_range: [7f067, 7f068) PFNs busy > [ 7.161139] alloc_contig_range: [7f070, 7f071) PFNs busy > [ 7.167295] alloc_contig_range: [7f071, 7f072) PFNs busy > [ 7.173413] alloc_contig_range: [7f072, 7f073) PFNs busy > [ 7.181387] alloc_contig_range: [7f073, 7f074) PFNs busy > [ 7.190623] alloc_contig_range: [7f074, 7f075) PFNs busy > [ 7.196668] alloc_contig_range: [7f075, 7f076) PFNs busy > [ 7.202793] alloc_contig_range: [7f076, 7f077) PFNs busy > [ 7.254911] hub 7-1:1.0: USB hub found > [ 7.259878] hub 7-1:1.0: 4 ports detected > [ 7.322543] rockchip-drm display-subsystem: master bind failed: -12 > [ 7.329619] rockchip-vop: probe of ff900000.vop failed with error -12 Full dmesg: https://gist.github.com/jakob-tsd/33cf395e355bf9bb6956c36438d999e7 I have bisected the "master bind failed" down to: > commit 9176a303d971dc0fb35469c531c0d263667d2277 > Author: Jeffy Chen <jeffy.chen at rock-chips.com> > Date: Fri Mar 23 15:38:10 2018 +0800 > > iommu/rockchip: Use IOMMU device for dma mapping operations > > Use the first registered IOMMU device for dma mapping operations, and > drop the domain platform device. > > This is similar to exynos iommu driver. > > Signed-off-by: Jeffy Chen <jeffy.chen at rock-chips.com> > Reviewed-by: Tomasz Figa <tfiga at chromium.org> > Reviewed-by: Robin Murphy <robin.murphy at arm.com> > Signed-off-by: Joerg Roedel <jroedel at suse.de> Moving to one commit earlier brings the screen to life. Just with colorful garbage, but I guess that's a different problem. Is this a known issue with the IOMMU change? Thanks, Jakob