diff mbox series

[v4,4/4] PCI: hv: Only queue a new work in hv_pci_devices_present() if necessary

Message ID KL1P15301MB0006CFED2B13C56CDDD2A153BFD00@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
State Accepted
Delegated to: Lorenzo Pieralisi
Headers show
Series [v4,1/4] PCI: hv: Fix a comment typo in _hv_pcifront_read_config() | expand

Commit Message

Dexuan Cui March 15, 2018, 2:22 p.m. UTC 
If there is a pending work, we just need to add the new dr into
the dr_list.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jack Morgenstein <jackm@mellanox.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/pci/host/pci-hyperv.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 0dc2ecdbbe45..50cdefe3f6d3 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1789,6 +1789,7 @@  static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
 	struct hv_dr_state *dr;
 	struct hv_dr_work *dr_wrk;
 	unsigned long flags;
+	bool pending_dr;
 
 	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
 	if (!dr_wrk)
@@ -1812,11 +1813,21 @@  static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
 	}
 
 	spin_lock_irqsave(&hbus->device_list_lock, flags);
+	/*
+	 * If pending_dr is true, we have already queued a work,
+	 * which will see the new dr. Otherwise, we need to
+	 * queue a new work.
+	 */
+	pending_dr = !list_empty(&hbus->dr_list);
 	list_add_tail(&dr->list_entry, &hbus->dr_list);
 	spin_unlock_irqrestore(&hbus->device_list_lock, flags);
 
-	get_hvpcibus(hbus);
-	queue_work(hbus->wq, &dr_wrk->wrk);
+	if (pending_dr) {
+		kfree(dr_wrk);
+	} else {
+		get_hvpcibus(hbus);
+		queue_work(hbus->wq, &dr_wrk->wrk);
+	}
 }
 
 /**