[PATCH 1/2] PCI: Make pci_msi_setup_pci_dev() non-static for use by arch code

Michael Ellerman mpe at ellerman.id.au
Mon Aug 24 22:42:46 AEST 2015

From: "Guilherme G. Piccoli" <gpiccoli at linux.vnet.ibm.com>

Commit 1851617cd2da ("PCI/MSI: Disable MSI at enumeration even if kernel
doesn't support MSI") changed the location of the code that initialises
dev->msi_cap/msix_cap and then disables MSI/MSI-X interrupts at PCI
probe time in devices that have this flag set. It moved the code from
pci_msi_init_pci_dev() to a new function named pci_msi_setup_pci_dev(),
called by pci_setup_device().

The pseries PCI probing code does not call pci_setup_device(), so since
the aforementioned commit the function pci_msi_setup_pci_dev() is not
called and MSI/MSI-X interrupts are left enabled. Additionally because
dev->msi_cap/msix_cap are not initialised no driver can ever enable

To fix this, the pseries PCI probe should manually call
pci_msi_setup_pci_dev(), so this patch makes it non-static.

Fixes: 1851617cd2da ("PCI/MSI: Disable MSI at enumeration even if kernel doesn't support MSI")
[mpe: Update change log to mention dev->msi_cap/msix_cap]
Signed-off-by: Guilherme G. Piccoli <gpiccoli at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
 drivers/pci/probe.c | 2 +-
 include/linux/pci.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

Bjorn, I plan to put this series in my fixes branch and ask Linus to pull it
before the 4.2 release. Unless you want to take it.

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b978bbfe044c..f6ae0d0052eb 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1108,7 +1108,7 @@ int pci_cfg_space_size(struct pci_dev *dev)
-static void pci_msi_setup_pci_dev(struct pci_dev *dev)
+void pci_msi_setup_pci_dev(struct pci_dev *dev)
 	 * Disable the MSI hardware to avoid screaming interrupts
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8a0321a8fb59..860c751810fc 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1202,6 +1202,7 @@ struct msix_entry {
 	u16	entry;	/* driver uses to specify entry, OS writes */
+void pci_msi_setup_pci_dev(struct pci_dev *dev);
 int pci_msi_vec_count(struct pci_dev *dev);

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