Please use this as your base
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5485883..8a277d7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2018,22 +2018,25 @@ void pci_enable_ari(struct pci_dev *dev)
u32 cap;
struct pci_dev *bridge;
- if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
- return;
-
- if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI))
+ if (pcie_ari_disabled || !pci_is_pcie(dev))
return;
bridge = dev->bus->self;
- if (!bridge)
+ if (!bridge || !list_empty(bridge->bus_list))
return;
-
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_ARI))
return;
- pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI);
- bridge->ari_enabled = 1;
+ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
+ pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_ARI);
+ bridge->ari_enabled = 1;
+ } else {
+ pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_ARI);
+ bridge->ari_enabled = 0;
+ }
}
/**
On 2012-10-9 16:14, Yijing Wang wrote:
> On 2012/10/9 15:51, Jiang Liu wrote:
>> When scanning PCI devices for hot-add, it guarantee function 0 is scanned
>> at first. And when destroying PCI devices for hot-removal, we also need to
>> destroy function 0 at last, but currently there's no such guarantees.
>>
>
> This is an issue, btw in pciehp now only try to hot remove fun from 0 --> 8,
> ARI device supports up to 256 function device.
> for (j = 0; j < 8; j++) {
> struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));
> if (!temp)
> continue;
>
>
>> On 2012-10-9 15:42, Yijing Wang wrote:
>>> On 2012/10/9 11:42, Jiang Liu wrote:
>>>> How about this patch, which disables ARI when adding new PCI devices?
>>>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>>>> index 5485883..c841aa6 100644
>>>> --- a/drivers/pci/pci.c
>>>> +++ b/drivers/pci/pci.c
>>>> @@ -2016,13 +2016,14 @@ void pci_free_cap_save_buffers(struct pci_dev *dev)
>>>> void pci_enable_ari(struct pci_dev *dev)
>>>> {
>>>
>>> I think it's ok. Delay to disable ARI until next hot add is safe.
>>> Maybe rename as pci_configure_ari is better.
>>>
>>>> u32 cap;
>>>> + bool enable = true;
>>>> struct pci_dev *bridge;
>>>>
>>>> if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
>>>> return;
>>>>
>>>> if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI))
>>>> - return;
>>>> + enable = false;
>>>>
>>>> bridge = dev->bus->self;
>>>> if (!bridge)
>>>> @@ -2032,8 +2033,15 @@ void pci_enable_ari(struct pci_dev *dev)
>>>> if (!(cap & PCI_EXP_DEVCAP2_ARI))
>>>> return;
>>>>
>>>> - pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI);
>>>> - bridge->ari_enabled = 1;
>>>> + if (enable) {
>>>> + pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
>>>> + PCI_EXP_DEVCTL2_ARI);
>>>> + bridge->ari_enabled = 1;
>>>> + } else {
>>>> + pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
>>>> + PCI_EXP_DEVCTL2_ARI);
>>>> + bridge->ari_enabled = 0;
>>>> + }
>>>> }
>>>>
>>>> /**
>>>>
>>>> On 2012-10-9 11:03, Yijing Wang wrote:
>>>>> pci_enable_ari will be called if an ARI pci device found, then set its bridge ARI Forwarding Enable
>>>>> bit in Device Control 2 Register. But the bridge ARI Forwarding Enable bit will never be cleared
>>>>> when an ARI device hot removed.
>>>>>
>>>>> my steps:
>>>>> 1. Hot add an ARI pci device;
>>>>> 2. Hot remove the ARI pci device;
>>>>> 3. Hot add an non ARI pci device;
>>>>>
>>>>> In this case, after setp 3, we could only find fun 0 of non ARI pci device because of its bridge ARI Forwarding Enable
>>>>> bit set.
>>>>>
>>>>> As PCIe Spec 2.0(6.13/441) recommends:
>>>>> "Following a hot-plug event below a Downstream Port, it is strongly recommended that software
>>>>> Clear the ARI Forwarding Enable bit in the Downstream Port until software determines that a
>>>>> newly added component is in fact an ARI Device"
>>>>>
>>>>> This series of patches fix this problem.
>>>>>
>>>>> Yijing Wang (7):
>>>>> PCI: rework pci_enable_ari for support disable ari forwarding
>>>>> PCI, acpiphp: disable ARI forwarding for acpiphp
>>>>> PCI, pciehp: disable ARI forwarding for pciehp
>>>>> PCI, cpqphp: disable ARI forwarding for cpqphp
>>>>> PCI, shpchp: disable ARI forwarding for shpchp
>>>>> PCI, sgi: disable ARI forwarding for sgiphp
>>>>> PCI, ibmphp: disable ARI forwarding for ibmphp
>>>>>
>>>>> drivers/pci/hotplug/acpiphp_glue.c | 1 +
>>>>> drivers/pci/hotplug/cpci_hotplug_pci.c | 1 +
>>>>> drivers/pci/hotplug/cpqphp_pci.c | 1 +
>>>>> drivers/pci/hotplug/ibmphp_core.c | 1 +
>>>>> drivers/pci/hotplug/pciehp_pci.c | 1 +
>>>>> drivers/pci/hotplug/sgi_hotplug.c | 1 +
>>>>> drivers/pci/hotplug/shpchp_pci.c | 1 +
>>>>> drivers/pci/pci.c | 16 +++++++++++-----
>>>>> drivers/pci/pci.h | 2 +-
>>>>> drivers/pci/probe.c | 2 +-
>>>>> 10 files changed, 20 insertions(+), 7 deletions(-)
>>>>>
>>>>>
>>>>>
>>>>> .
>>>>>
>>>>
>>>>
>>>>
>>>> .
>>>>
>>>
>>>
>>
>>
>>
>> .
>>
>
>
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