[4.2.y-ckt stable] Patch "PCI/MSI: Initialize MSI capability for all architectures" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    PCI/MSI: Initialize MSI capability for all architectures

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 70b5d31f71bca0a683c14380d515e6d8e4d80f01 Mon Sep 17 00:00:00 2001
From: "Guilherme G. Piccoli" <gpiccoli at linux.vnet.ibm.com>
Date: Wed, 21 Oct 2015 12:17:35 -0200
Subject: PCI/MSI: Initialize MSI capability for all architectures

commit e80e7edc55ba711f3fe23975061b3f1c336ceb95 upstream.

1851617cd2da ("PCI/MSI: Disable MSI at enumeration even if kernel doesn't
support MSI") moved dev->msi_cap and dev->msix_cap initialization from the
pci_init_capabilities() path (used on all architectures) to the
pci_setup_device() path (not used on Open Firmware architectures).

This broke MSI or MSI-X on Open Firmware machines.  4d9aac397a5d
("powerpc/PCI: Disable MSI/MSI-X interrupts at PCI probe time in OF case")
fixed it for PowerPC but not for SPARC.

Set up MSI and MSI-X (initialize msi_cap and msix_cap and disable MSI and
MSI-X) in pci_init_capabilities() so all architectures do it the same way.

This reverts 4d9aac397a5d since this patch fixes the problem generically
for both PowerPC and SPARC.

[bhelgaas: changelog, make pci_msi_setup_pci_dev() static]
Fixes: 1851617cd2da ("PCI/MSI: Disable MSI at enumeration even if kernel doesn't support MSI")
Signed-off-by: Guilherme G. Piccoli <gpiccoli at linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>

Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/powerpc/kernel/pci_of_scan.c | 3 ---
 drivers/pci/probe.c               | 7 ++++---
 include/linux/pci.h               | 2 --
 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
index efc3fa5..42e02a2 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -191,9 +191,6 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,

 	pci_device_add(dev, bus);

-	/* Setup MSI caps & disable MSI/MSI-X interrupts */
-	pci_msi_setup_pci_dev(dev);
-
 	return dev;
 }
 EXPORT_SYMBOL(of_create_pci_dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f6ae0d0..8e4ad97 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1108,7 +1108,7 @@ int pci_cfg_space_size(struct pci_dev *dev)

 #define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)

-void pci_msi_setup_pci_dev(struct pci_dev *dev)
+static void pci_msi_setup_pci_dev(struct pci_dev *dev)
 {
 	/*
 	 * Disable the MSI hardware to avoid screaming interrupts
@@ -1179,8 +1179,6 @@ int pci_setup_device(struct pci_dev *dev)
 	/* "Unknown power state" */
 	dev->current_state = PCI_UNKNOWN;

-	pci_msi_setup_pci_dev(dev);
-
 	/* Early fixups, before probing the BARs */
 	pci_fixup_device(pci_fixup_early, dev);
 	/* device class may be changed after fixup */
@@ -1530,6 +1528,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	/* MSI/MSI-X list */
 	pci_msi_init_pci_dev(dev);

+	/* Setup MSI caps & disable MSI/MSI-X interrupts */
+	pci_msi_setup_pci_dev(dev);
+
 	/* Buffers for saving PCIe and PCI-X capabilities */
 	pci_allocate_cap_save_buffers(dev);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 1d4eb60..5b098ed 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1204,8 +1204,6 @@ struct msix_entry {
 	u16	entry;	/* driver uses to specify entry, OS writes */
 };

-void pci_msi_setup_pci_dev(struct pci_dev *dev);
-
 #ifdef CONFIG_PCI_MSI
 int pci_msi_vec_count(struct pci_dev *dev);
 void pci_msi_shutdown(struct pci_dev *dev);
--
1.9.1