Michael reports that after the blamed patch, unbinding a VF would cause
these transactions to remain pending, and trigger some warnings with the
DMA API debug:
$ echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/sriov_numvfs
pci 0000:00:01.0: [1957:ef00] type 00 class 0x020001
fsl_enetc_vf 0000:00:01.0: Adding to iommu group 19
fsl_enetc_vf 0000:00:01.0: enabling device (0000 -> 0002)
fsl_enetc_vf 0000:00:01.0 eno0vf0: renamed from eth0
$ echo 0 > /sys/bus/pci/devices/0000\:00\:00.0/sriov_numvfs
DMA-API: pci 0000:00:01.0: device driver has pending DMA allocations while released from device [count=1]
One of leaked entries details: [size=2048 bytes] [mapped with DMA_BIDIRECTIONAL] [mapped as coherent]
WARNING: CPU: 0 PID: 2547 at kernel/dma/debug.c:853 dma_debug_device_change+0x174/0x1c8
(...)
Call trace:
dma_debug_device_change+0x174/0x1c8
blocking_notifier_call_chain+0x74/0xa8
device_release_driver_internal+0x18c/0x1f0
device_release_driver+0x20/0x30
pci_stop_bus_device+0x8c/0xe8
pci_stop_and_remove_bus_device+0x20/0x38
pci_iov_remove_virtfn+0xb8/0x128
sriov_disable+0x3c/0x110
pci_disable_sriov+0x24/0x30
enetc_sriov_configure+0x4c/0x108
sriov_numvfs_store+0x11c/0x198
(...)
DMA-API: Mapped at:
dma_entry_alloc+0xa4/0x130
debug_dma_alloc_coherent+0xbc/0x138
dma_alloc_attrs+0xa4/0x108
enetc_setup_cbdr+0x4c/0x1d0
enetc_vf_probe+0x11c/0x250
pci 0000:00:01.0: Removing from iommu group 19
This happens because stupid me moved enetc_teardown_cbdr outside of
enetc_free_si_resources, but did not bother to keep calling
enetc_teardown_cbdr from all the places where enetc_free_si_resources
was called. In particular, now it is no longer called from the main
unbind function, just from the probe error path.
Fixes:
4b47c0b81ffd ("net: enetc: don't initialize unused ports from a separate code path")
Reported-by: Michael Walle <michael@walle.cc>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>