From d6e1ab9ea3514840e4f32957c457b094646c2e9d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 22 Aug 2017 23:22:42 -0700 Subject: [PATCH] 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 6d48ceb27af1 ("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: 6d48ceb27af1 ("nfp: allocate a private workqueue for driver work") Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_main.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.c b/drivers/net/ethernet/netronome/nfp/nfp_main.c index d67969d..3f199db2 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_main.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c @@ -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; } -- 2.7.4