Error tearing down ftgmac100 in qemu

[shenki]

# kexec -e
[   35.979554] ftgmac100 1e660000.ethernet eth0: NCSI interface down
[   35.981374] ------------[ cut here ]------------
[   35.981602] WARNING: CPU: 0 PID: 509 at arch/arm/mm/dma-mapping.c:903 __arm_dma_free.constprop.3+0x10c/0x12c
[   35.981921] Freeing invalid buffer a09ca000
[   35.982240] CPU: 0 PID: 509 Comm: kexec Not tainted 4.13.0-00185-g89055c704638 #723
[   35.982504] Hardware name: ASpeed SoC
[   35.983221] [<80010488>] (unwind_backtrace) from [<8000da6c>] (show_stack+0x20/0x24)
[   35.983526] [<8000da6c>] (show_stack) from [<80404834>] (dump_stack+0x20/0x28)
[   35.983775] [<80404834>] (dump_stack) from [<80018f34>] (__warn+0xe0/0x108)
[   35.984019] [<80018f34>] (__warn) from [<80018fa0>] (warn_slowpath_fmt+0x44/0x4c)
[   35.984337] [<80018fa0>] (warn_slowpath_fmt) from [<80011d5c>] (__arm_dma_free.constprop.3+0x10c/0x12c)
[   35.984643] [<80011d5c>] (__arm_dma_free.constprop.3) from [<80011da0>] (arm_dma_free+0x24/0x2c)
[   35.984947] [<80011da0>] (arm_dma_free) from [<80294c00>] (ftgmac100_free_rings+0x114/0x208)
[   35.985239] [<80294c00>] (ftgmac100_free_rings) from [<80294d94>] (ftgmac100_stop+0xa0/0xbc)
[   35.985532] [<80294d94>] (ftgmac100_stop) from [<8032c86c>] (__dev_close_many+0xa8/0xfc)
[   35.985847] [<8032c86c>] (__dev_close_many) from [<8032c8f8>] (__dev_close+0x38/0x4c)
[   35.986125] [<8032c8f8>] (__dev_close) from [<80334728>] (__dev_change_flags+0x98/0x160)
[   35.986423] [<80334728>] (__dev_change_flags) from [<80334818>] (dev_change_flags+0x28/0x58)
[   35.986723] [<80334818>] (dev_change_flags) from [<8039ec0c>] (devinet_ioctl+0x640/0x740)
[   35.987034] [<8039ec0c>] (devinet_ioctl) from [<803a0b64>] (inet_ioctl+0x1a4/0x1d0)
[   35.987320] [<803a0b64>] (inet_ioctl) from [<80316914>] (sock_ioctl+0x11c/0x27c)
[   35.987591] [<80316914>] (sock_ioctl) from [<800fcc60>] (do_vfs_ioctl+0xa0/0x774)
[   35.987912] [<800fcc60>] (do_vfs_ioctl) from [<800fd378>] (SyS_ioctl+0x44/0x68)
[   35.988175] [<800fd378>] (SyS_ioctl) from [<8000a520>] (ret_fast_syscall+0x0/0x34)
[   35.988500] ---[ end trace 5db2d09d6d658cf3 ]---