Commit 020d5024 authored May 23, 2006 by Rajesh Shah Committed by Greg Kroah-Hartman Jun 21, 2006

[PATCH] PCI: Allow MSI to work on kexec kernel



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 <rajesh.shah@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent 1edab4a1

drivers/pci/msi.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -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;

Admin message