[PATCH 3/4] PCI: hv: Do not queue new work items on hibernation

[Dexuan Cui]

We must make sure there is no pending work items before we call
vmbus_close().

Signed-off-by: Dexuan Cui <de...@microsoft.com>
---
 drivers/pci/controller/pci-hyperv.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c 
b/drivers/pci/controller/pci-hyperv.c
index 3b77a3a..2655df2 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -422,6 +422,7 @@ enum hv_pcibus_state {
        hv_pcibus_init = 0,
        hv_pcibus_probed,
        hv_pcibus_installed,
+       hv_pcibus_removing,
        hv_pcibus_removed,
        hv_pcibus_maximum
 };
@@ -1841,6 +1842,12 @@ static void hv_pci_devices_present(struct 
hv_pcibus_device *hbus,
        unsigned long flags;
        bool pending_dr;
 
+       if (hbus->state == hv_pcibus_removing) {
+               dev_info(&hbus->hdev->device,
+                        "PCI VMBus BUS_RELATIONS: ignored\n");
+               return;
+       }
+
        dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
        if (!dr_wrk)
                return;
@@ -1957,11 +1964,19 @@ static void hv_eject_device_work(struct work_struct 
*work)
  */
 static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
 {
+       struct hv_pcibus_device *hbus = hpdev->hbus;
+       struct hv_device *hdev = hbus->hdev;
+
+       if (hbus->state == hv_pcibus_removing) {
+               dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
+               return;
+       }
+
        hpdev->state = hv_pcichild_ejecting;
        get_pcichild(hpdev);
        INIT_WORK(&hpdev->wrk, hv_eject_device_work);
-       get_hvpcibus(hpdev->hbus);
-       queue_work(hpdev->hbus->wq, &hpdev->wrk);
+       get_hvpcibus(hbus);
+       queue_work(hbus->wq, &hpdev->wrk);
 }
 
 /**
@@ -2757,9 +2772,21 @@ static int hv_pci_remove(struct hv_device *hdev)
 static int hv_pci_suspend(struct hv_device *hdev)
 {
        struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
+       enum hv_pcibus_state old_state;
        int ret;
 
-       /* XXX: Need to prevent any new work from being queued. */
+       tasklet_disable(&hdev->channel->callback_event);
+
+       /* Change the hbus state to prevent new work items. */
+       old_state = hbus->state;
+       if (hbus->state == hv_pcibus_installed)
+               hbus->state = hv_pcibus_removing;
+
+       tasklet_enable(&hdev->channel->callback_event);
+
+       if (old_state != hv_pcibus_installed)
+               return -EINVAL;
+
        flush_workqueue(hbus->wq);
 
        ret = hv_pci_bus_exit(hdev, true);
-- 
1.8.3.1