[PATCH v3]PCI: hv: fix PCI-BUS domainID corruption

[Sridhar Pitchai]

Whenever PCI bus is added, HyperV guarantees the BUS id is unique. Even
with that when a first device is added to the bus, it overrides bus domain
ID with the device serial number. Sometime this can result in BUS ID not
being unique. In this case, when PCI_BUS and a device to bus is added, the
first device overwrites the bus domain ID to the device serial number,
which is 0. Since there exsist a PCI bus with domain ID 0 already the PCI
bus addition fails. This patch make sure when a device is added to a bus,
it never updated the bus domain ID. Since we have the transparent SRIOV
mode now, the short VF device name is no longer needed.

Fixes: 4a9b0933bdfc("PCI:hv:Use device serial number as PCI domain")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sridhar Pitchai <srpitcha@xxxxxxxxxxxxx>
---

Changes in v3:
* fix the commit comment. [KY Srinivasan, Michael Kelley]
---
 drivers/pci/host/pci-hyperv.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 2faf38e..ac67e56 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1518,17 +1518,6 @@ static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
 	get_pcichild(hpdev, hv_pcidev_ref_childlist);
 	spin_lock_irqsave(&hbus->device_list_lock, flags);
 
-	/*
-	 * When a device is being added to the bus, we set the PCI domain
-	 * number to be the device serial number, which is non-zero and
-	 * unique on the same VM.  The serial numbers start with 1, and
-	 * increase by 1 for each device.  So device names including this
-	 * can have shorter names than based on the bus instance UUID.
-	 * Only the first device serial number is used for domain, so the
-	 * domain number will not change after the first device is added.
-	 */
-	if (list_empty(&hbus->children))
-		hbus->sysdata.domain = desc->ser;
 	list_add_tail(&hpdev->list_entry, &hbus->children);
 	spin_unlock_irqrestore(&hbus->device_list_lock, flags);
 	return hpdev;
-- 
2.7.4