It looks like the linux-next commit “of/platform: Pause/resume sync state during init and of_platform_populate()” [1] Introduced a warning while booting arm64. [1] https://lore.kernel.org/lkml/20190731221721.187713-6-saravanak@xxxxxxxxxx/ [ 93.449300][ T1] arm-smmu-v3 arm-smmu-v3.4.auto: ias 44-bit, oas 44-bit (features 0x0000170d) [ 93.464873][ T1] arm-smmu-v3 arm-smmu-v3.4.auto: allocated 524288 entries for cmdq [ 93.485481][ T1] arm-smmu-v3 arm-smmu-v3.4.auto: allocated 524288 entries for evtq [ 93.496320][ T1] arm-smmu-v3 arm-smmu-v3.5.auto: option mask 0x2 [ 93.502917][ T1] arm-smmu-v3 arm-smmu-v3.5.auto: ias 44-bit, oas 44-bit (features 0x0000170d) [ 93.621818][ T1] arm-smmu-v3 arm-smmu-v3.5.auto: allocated 524288 entries for cmdq [ 93.643000][ T1] arm-smmu-v3 arm-smmu-v3.5.auto: allocated 524288 entries for evtq [ 94.519445][ T1] libphy: Fixed MDIO Bus: probed [ 94.524649][ T1] EFI Variables Facility v0.08 2004-May-17 [ 94.601166][ T1] NET: Registered protocol family 17 [ 94.766008][ T1] zswap: loaded using pool lzo/zbud [ 94.774745][ T1] kmemleak: Kernel memory leak detector initialized (mempool size: 16384) [ 94.774756][ T1699] kmemleak: Automatic memory scanning thread started [ 94.812338][ T1368] pcieport 0000:0f:00.0: Adding to iommu group 0 [ 94.984466][ T1] ------------[ cut here ]------------ [ 94.989827][ T1] Unmatched sync_state pause/resume! [ 94.989894][ T1] WARNING: CPU: 25 PID: 1 at drivers/base/core.c:691 device_links_supplier_sync_state_resume+0x100/0x128 [ 95.006062][ T1] Modules linked in: [ 95.009815][ T1] CPU: 25 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc3-next-20190806+ #11 [ 95.018161][ T1] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 [ 95.028593][ T1] pstate: 60400009 (nZCv daif +PAN -UAO) [ 95.034077][ T1] pc : device_links_supplier_sync_state_resume+0x100/0x128 [ 95.041124][ T1] lr : device_links_supplier_sync_state_resume+0x100/0x128 [ 95.048167][ T1] sp : 34ff800806e6fbc0 [ 95.052172][ T1] x29: 34ff800806e6fc00 x28: 0000000000000000 [ 95.058177][ T1] x27: 0000000000000000 x26: 0000000000000000 [ 95.064181][ T1] x25: 0000000000000038 x24: 0000000000000000 [ 95.070185][ T1] x23: 0000000000000000 x22: 0000000000000019 [ 95.076189][ T1] x21: 0000000000000000 x20: f9ff808b804e6c50 [ 95.082193][ T1] x19: ffff100014a6e600 x18: 0000000000000040 [ 95.088197][ T1] x17: 0000000000000000 x16: 86ff80099d581b50 [ 95.094201][ T1] x15: 0000000000000000 x14: ffff100010086d1c [ 95.100205][ T1] x13: ffff1000109d8688 x12: ffffffffffffffff [ 95.106209][ T1] x11: 00000000000000f9 x10: ffff0808b804e6c6 [ 95.112213][ T1] x9 : 4b71ad522c851d00 x8 : 4b71ad522c851d00 [ 95.118217][ T1] x7 : 6170206574617473 x6 : ffff100014076972 [ 95.124221][ T1] x5 : 34ff800806e6f8f0 x4 : 000000000000000f [ 95.130225][ T1] x3 : ffff1000101bfa5c x2 : 0000000000000001 [ 95.136229][ T1] x1 : 0000000000000001 x0 : 0000000000000022 [ 95.142233][ T1] Call trace: [ 95.145374][ T1] device_links_supplier_sync_state_resume+0x100/0x128 [ 95.152074][ T1] of_platform_sync_state_init+0x10/0x1c [ 95.157557][ T1] do_one_initcall+0x2f8/0x600 [ 95.162172][ T1] do_initcall_level+0x37c/0x3fc [ 95.166959][ T1] do_basic_setup+0x34/0x4c [ 95.171313][ T1] kernel_init_freeable+0x188/0x24c [ 95.176363][ T1] kernel_init+0x18/0x334 [ 95.180543][ T1] ret_from_fork+0x10/0x18 [ 95.184809][ T1] ---[ end trace a9ea68c902540fe5 ]--- [ 95.269085][ T1] Freeing unused kernel memory: 28672K [ 101.069860][ T1] Checked W+X mappings: passed, no W+X pages found [ 101.076265][ T1] Run /init as init process [ 101.186359][ T1] systemd[1]: System time before build time, advancing clock.
