[+cc Christoph] On Sun, Sep 09, 2018 at 04:26:37PM +0800, Tonghao Zhang wrote: > Hi all, > When I enable pci msi or msix more than once, the kernel will panic. > Now we just use the WARN_ON, should we add check for that has been > enabled. > This needs a signed-off-by before I can apply it. See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n416 A WARN_ON() shouldn't cause the kernel to panic. Do you mean that it causes a backtrace? I think that's the intended behavior, because calling this twice would be a driver bug, and we want to find and fix those bugs. > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index f2ef896..324840f 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -958,7 +958,9 @@ static int __pci_enable_msix(struct pci_dev *dev, > struct msix_entry *entries, > } > } > } > - WARN_ON(!!dev->msix_enabled); > + > + if (dev->msix_enabled) > + return -EINVAL; > > /* Check whether driver already requested for MSI irq */ > if (dev->msi_enabled) { > @@ -1028,7 +1030,8 @@ static int __pci_enable_msi_range(struct pci_dev > *dev, int minvec, int maxvec, > if (!pci_msi_supported(dev, minvec)) > return -EINVAL; > > - WARN_ON(!!dev->msi_enabled); > + if (dev->msi_enabled) > + return -EINVAL; > > /* Check whether driver already requested MSI-X irqs */ > if (dev->msix_enabled) {
