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

2015-08-24 Thread Michael Ellerman 
From: Guilherme G. Piccoli gpicc...@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
MSI/MSI-X.

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 gpicc...@linux.vnet.ibm.com
Signed-off-by: Michael Ellerman m...@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)
 
 #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
 
-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);
 
 #ifdef CONFIG_PCI_MSI
 int pci_msi_vec_count(struct pci_dev *dev);
-- 
2.1.4

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

2015-08-18 Thread Michael Ellerman 
Hi Guilherme,

Thanks for the patches.

On Tue, 2015-08-18 at 18:13 -0300, Guilherme G. Piccoli wrote:
 Commit 1851617cd2 (PCI/MSI: Disable MSI at enumeration even if kernel
 doesn't support MSI) changed the location of the code that 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().

OK.

 Since then, the pSeries platform of the powerpc architecture needs to
 disable MSI at PCI probe time manually, as the code flow doesn't
 reach pci_setup_device(). 

 For doing so, it wants to call
 pci_msi_setup_pci_dev(). This patch makes the required function
 non-static, so that it will be called on PCI probe path on powerpc pSeries
 platform in next patch.

I didn't follow that entirely, I think you mean something like:

  The pseries PCI probing code does not call pci_setup_device(), so since
  commit 1851617cd2 pci_msi_setup_pci_dev() is not called and MSIs are left
  enabled, which is a bug.

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


Does that look OK?

Also you haven't CC'ed the original author of the commit, or the PCI
maintainer, or the relevant lists.

That would be:

Michael S. Tsirkin m...@redhat.com
Bjorn Helgaas bhelg...@google.com
linux-...@vger.kernel.org
linux-ker...@vger.kernel.org


And finally both patches should have a fixes line, such as:

Fixes: 1851617cd2da (PCI/MSI: Disable MSI at enumeration even if kernel 
doesn't support MSI)

cheers



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

2015-08-18 Thread Guilherme G. Piccoli 
Commit 1851617cd2 (PCI/MSI: Disable MSI at enumeration even if kernel
doesn't support MSI) changed the location of the code that 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().

Since then, the pSeries platform of the powerpc architecture needs to
disable MSI at PCI probe time manually, as the code flow doesn't
reach pci_setup_device(). For doing so, it wants to call
pci_msi_setup_pci_dev(). This patch makes the required function
non-static, so that it will be called on PCI probe path on powerpc pSeries
platform in next patch.

Signed-off-by: Guilherme G. Piccoli gpicc...@linux.vnet.ibm.com
---
 drivers/pci/probe.c | 2 +-
 include/linux/pci.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cefd636..520c5b6 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1103,7 +1103,7 @@ int pci_cfg_space_size(struct pci_dev *dev)
 
 #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
 
-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 8a0321a..860c751 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);
 
 #ifdef CONFIG_PCI_MSI
 int pci_msi_vec_count(struct pci_dev *dev);
-- 
2.1.0

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