From owner-linux-pci@atrey.karlin.mff.cuni.cz Tue May 23 10:16:46 2006 Date: Tue, 23 May 2006 10:14:36 -0700 From: Rajesh Shah To: gregkh@suse.de, Subject: PCI: Allow MSI to work on kexec kernel Message-ID: <20060523101436.A25249@unix-os.sc.intel.com> Content-Disposition: inline We recently ran into a problem where the e1000 device failed to work properly on the kexec kernel. MSI was enabled for the device in the main kernel when it crashed. The e1000 driver tried to enable MSI on the kexec kernel, but the code bailed early when it found that MSI was already enabled in the hardware, even though the software state was not properly set up in the kexec'd kernel. This patch fixes the problem by moving the early return to after making sure that the software state is properly initialized. Signed-off-by: Rajesh Shah Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- gregkh-2.6.orig/drivers/pci/msi.c +++ gregkh-2.6/drivers/pci/msi.c @@ -940,14 +940,13 @@ int pci_enable_msi(struct pci_dev* dev) if (!pos) return -EINVAL; - pci_read_config_word(dev, msi_control_reg(pos), &control); - if (control & PCI_MSI_FLAGS_ENABLE) - return 0; /* Already in MSI mode */ - if (!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) { /* Lookup Sucess */ unsigned long flags; + pci_read_config_word(dev, msi_control_reg(pos), &control); + if (control & PCI_MSI_FLAGS_ENABLE) + return 0; /* Already in MSI mode */ spin_lock_irqsave(&msi_lock, flags); if (!vector_irq[dev->irq]) { msi_desc[dev->irq]->msi_attrib.state = 0;