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I looked at the code and didn't see where pci_cfg_access_lock() is taken... Thanks! > - mlx5_crdump_collect() trying to acquire the pci_cfg_access_lock() > while devlink_health_report() had acquired the devlink lock.> > Move the check for pci_channel_offline prior to acquiring the > pci_cfg_access_lock in mlx5_vsc_gw_lock since collecting the crdump will > fail anyhow while PCI error recovery is running. > > Fixes: 33afbfcc105a ("net/mlx5: Stop waiting for PCI if pci channel is offline") > Signed-off-by: Gerd Bayer > --- > > Hi all, > > while the initial hit was recorded during "random" testing, where PCI > error recovery and poll_health() tripped almost simultaneously, I found > a way to reproduce a very similar hang at will on s390: > > Inject a PCI error recovery event on a Physical Function with > zpcictl --reset-fw > > then request a crdump with > devlink health dump show pci/ reporter fw_fatal > > With the patch applied I didn't get the hang but kernel logs showed: > [ 792.885743] mlx5_core 000a:00:00.0: mlx5_crdump_collect:51:(pid 1415): crdump: failed to lock vsc gw err -13 > > and the crdump request ended with: > kernel answers: Permission denied > > Thanks, Gerd > --- > drivers/net/ethernet/mellanox/mlx5/core/lib/pci_vsc.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/pci_vsc.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/pci_vsc.c > index 432c98f2626d..d2d3b57a57d5 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/pci_vsc.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/pci_vsc.c > @@ -73,16 +73,15 @@ int mlx5_vsc_gw_lock(struct mlx5_core_dev *dev) > u32 lock_val; > int ret; > > + if (pci_channel_offline(dev->pdev)) > + return -EACCES; > + > pci_cfg_access_lock(dev->pdev); > do { > if (retries > VSC_MAX_RETRIES) { > ret = -EBUSY; > goto pci_unlock; > } > - if (pci_channel_offline(dev->pdev)) { > - ret = -EACCES; > - goto pci_unlock; > - } > > /* Check if semaphore is already locked */ > ret = vsc_read(dev, VSC_SEMAPHORE_OFFSET, &lock_val); > -- > 2.48.1 >