Re: [PATCH v3 2/2] PCI: Add support for Enhanced Allocation devices
From: Sean O. Stalley <hidden>
Date: 2015-09-30 22:52:47
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On Tue, Sep 29, 2015 at 04:53:20PM -0700, David Daney wrote:
On 09/29/2015 03:47 PM, Sean O. Stalley wrote: [...]quoted
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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? -Sean