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Commit d6e1ab9e authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
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nfp: don't hold PF lock while enabling SR-IOV 



Enabling SR-IOV VFs will cause the PCI subsystem to schedule a
work and flush its workqueue.  Since the nfp driver schedules its
own work we can't enable VFs while holding driver load.  Commit
6d48ceb2 ("nfp: allocate a private workqueue for driver work")
tried to avoid this deadlock by creating a separate workqueue.
Unfortunately, due to the architecture of workqueue subsystem this
does not guarantee a separate thread of execution.  Luckily
we can simply take pci_enable_sriov() from under the driver lock.

Take pci_disable_sriov() from under the lock too for symmetry.

Fixes: 6d48ceb2 ("nfp: allocate a private workqueue for driver work")
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarSimon Horman <simon.horman@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2f19f50e

drivers/net/ethernet/netronome/nfp/nfp_main.c

+7 −9
Original line number Diff line number Diff line
@@ -98,21 +98,20 @@ static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs) 
	struct nfp_pf *pf = pci_get_drvdata(pdev);

	int err;



	mutex_lock(&pf->lock);



	if (num_vfs > pf->limit_vfs) {

		nfp_info(pf->cpp, "Firmware limits number of VFs to %u\n",

			 pf->limit_vfs);

		err = -EINVAL;

		goto err_unlock;

		return -EINVAL;

	}



	err = pci_enable_sriov(pdev, num_vfs);

	if (err) {

		dev_warn(&pdev->dev, "Failed to enable PCI SR-IOV: %d\n", err);

		goto err_unlock;

		return err;

	}



	mutex_lock(&pf->lock);



	err = nfp_app_sriov_enable(pf->app, num_vfs);

	if (err) {

		dev_warn(&pdev->dev,
@@ -129,9 +128,8 @@ static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs) 
	return num_vfs;



err_sriov_disable:

	pci_disable_sriov(pdev);

err_unlock:

	mutex_unlock(&pf->lock);

	pci_disable_sriov(pdev);

	return err;

#endif

	return 0;
@@ -158,10 +156,10 @@ static int nfp_pcie_sriov_disable(struct pci_dev *pdev) 


	pf->num_vfs = 0;



	mutex_unlock(&pf->lock);



	pci_disable_sriov(pdev);

	dev_dbg(&pdev->dev, "Removed VFs.\n");



	mutex_unlock(&pf->lock);

#endif

	return 0;

}