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Commit da27f4b3 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI: Add comment about needing pci_msi_off() even when CONFIG_PCI_MSI=n 



Per f5f2b131 ("msi: sanely support hardware level msi disabling"), we
want pci_msi_off() to work even if MSI support is not compiled into the
kernel, and there are existing callers that use it when CONFIG_PCI_MSI=n.
This adds a comment to that effect.

No functional change.

Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 699c1985

drivers/pci/pci.c

+9 −4
Original line number Diff line number Diff line
@@ -3059,18 +3059,23 @@ bool pci_check_and_unmask_intx(struct pci_dev *dev) 
EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);



/**

 * pci_msi_off - disables any msi or msix capabilities

 * pci_msi_off - disables any MSI or MSI-X capabilities

 * @dev: the PCI device to operate on

 *

 * If you want to use msi see pci_enable_msi and friends.

 * This is a lower level primitive that allows us to disable

 * msi operation at the device level.

 * If you want to use MSI, see pci_enable_msi() and friends.

 * This is a lower-level primitive that allows us to disable

 * MSI operation at the device level.

 */

void pci_msi_off(struct pci_dev *dev)

{

	int pos;

	u16 control;



	/*

	 * This looks like it could go in msi.c, but we need it even when

	 * CONFIG_PCI_MSI=n.  For the same reason, we can't use

	 * dev->msi_cap or dev->msix_cap here.

	 */

	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);

	if (pos) {

		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);