On 09/30/2015 03:50 PM, Sean O. Stalley wrote:

On Tue, Sep 29, 2015 at 04:53:20PM -0700, David Daney wrote:

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On 09/29/2015 03:47 PM, Sean O. Stalley wrote:
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diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6a9a111..7c60b16 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c

@@ -2148,6 +2148,284 @@ void pci_pm_init(struct pci_dev *dev)
  	}
  }

+static unsigned long pci_ea_set_flags(struct pci_dev *dev, u8 prop)
+{
+	unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_SIZEALIGN;

Why did you add the IORESOURCE_SIZEALIGN flag? EA allows for unaligned resources.

pci_bus_assign_resources() fails causing the devices to be unusable
if resource_alignment() returns zero.  The easiest fix for this was
to specify IORESOURCE_SIZEALIGN.

An alternative would be to change the code in setup-bus.c so that
for IORESOURCE_PCI_FIXED resources, it didn't barf.

I would do this alternative, but with a IORESOURCE_PCI_EA flag.

I don't think we need IORESOURCE_PCI_EA.  If a resource is tagged as
IORESOURCE_PCI_FIXED that means that it cannot be changed, we
shouldn't care why it is fixed (due to an EA capability for
example).  We just need to gracefully handle IORESOURCE_PCI_FIXED in
the places where things currently go wrong.

David Daney

I agree that we need to make sure fixed things stay fixed,
regardless of if they are fixed by EA or something else.

The question is: do we want to allow all fixed resources to be non-aligned, or just EA?

The alignment should only be important if a new address is being 
calculated for a BAR or behind the bridge memory/io region.  If the 
resource is fixed, I would almost say that "alignment" is an undefined 
concept.  So, in the places were we need special treatment for 
IORESOURCE_PCI_FIXED, I would argue that we shouldn't be use the 
resource alignment information.

David Daney

-Sean