On 2022/4/4 14:25, Jay Zhou wrote: > Call trace of PF SRIOV disable: > sriov_numvfs_store > device_lock <----------------- (1) get the device lock > ->sriov_configure # e.g. vfio_pci_sriov_configure > sriov_disable > pci_cfg_access_lock <--- (4) wait dev->block_cfg_access to be 0 > > Call trace of PF reset: > reset_store > pci_reset_function > pci_dev_lock > pci_cfg_access_lock <----- (2) set dev->block_cfg_access = 1 > device_lock <------------- (3) want to get the device lock > > These two oprations would wait for each other forever if the > code execution sequence is (1)(2)(3)(4). > > Let's get the device lock and then the config access lock in > pci_dev_lock(). > > Signed-off-by: Jay Zhou <jianjay.zhou@xxxxxxxxxx> The patch looks good to me, Reviewed-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx> I met the same problem and tried to fix it in the same way. It's worth to be merged if somebody meets the same problem again. https://lore.kernel.org/linux-pci/1583489997-17156-1-git-send-email-yangyicong@xxxxxxxxxxxxx/ > --- > drivers/pci/pci.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 9ecce435fb3f..61a6db1d21f6 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -5103,19 +5103,19 @@ static int pci_reset_bus_function(struct pci_dev *dev, bool probe) > > void pci_dev_lock(struct pci_dev *dev) > { > - pci_cfg_access_lock(dev); > /* block PM suspend, driver probe, etc. */ > device_lock(&dev->dev); > + pci_cfg_access_lock(dev); > } > EXPORT_SYMBOL_GPL(pci_dev_lock); > > /* Return 1 on successful lock, 0 on contention */ > int pci_dev_trylock(struct pci_dev *dev) > { > - if (pci_cfg_access_trylock(dev)) { > - if (device_trylock(&dev->dev)) > + if (device_trylock(&dev->dev)) { > + if (pci_cfg_access_trylock(dev)) > return 1; > - pci_cfg_access_unlock(dev); > + device_unlock(&dev->dev); > } > > return 0; > @@ -5124,8 +5124,8 @@ EXPORT_SYMBOL_GPL(pci_dev_trylock); > > void pci_dev_unlock(struct pci_dev *dev) > { > - device_unlock(&dev->dev); > pci_cfg_access_unlock(dev); > + device_unlock(&dev->dev); > } > EXPORT_SYMBOL_GPL(pci_dev_unlock); > >
