Since we serialize the present/eject work items now, we don't need the semaphore any more.

This is suggested by Michael Kelley.

Signed-off-by: Dexuan Cui decui@microsoft.com Cc: Vitaly Kuznetsov vkuznets@redhat.com Cc: Jack Morgenstein jackm@mellanox.com Cc: stable@vger.kernel.org Cc: Stephen Hemminger sthemmin@microsoft.com Cc: K. Y. Srinivasan kys@microsoft.com Cc: Michael Kelley (EOSG) Michael.H.Kelley@microsoft.com --- drivers/pci/host/pci-hyperv.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index aaee41faf55f..3a385212f666 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -447,7 +447,6 @@ struct hv_pcibus_device { spinlock_t device_list_lock; /* Protect lists below */ void __iomem *cfg_addr;

- struct semaphore enum_sem; struct list_head resources_for_children;

struct list_head children; @@ -1592,12 +1591,8 @@ static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, * It must also treat the omission of a previously observed device as * notification that the device no longer exists. * - * Note that this function is a work item, and it may not be - * invoked in the order that it was queued. Back to back - * updates of the list of present devices may involve queuing - * multiple work items, and this one may run before ones that - * were sent later. As such, this function only does something - * if is the last one in the queue. + * Note that this function is serialized with hv_eject_device_work(), + * because both are pushed to the ordered workqueue hbus->wq. */ static void pci_devices_present_work(struct work_struct *work) { @@ -1618,11 +1613,6 @@ static void pci_devices_present_work(struct work_struct *work)

INIT_LIST_HEAD(&removed);

- if (down_interruptible(&hbus->enum_sem)) { - put_hvpcibus(hbus); - return; - } - /* Pull this off the queue and process it if it was the last one. */ spin_lock_irqsave(&hbus->device_list_lock, flags); while (!list_empty(&hbus->dr_list)) { @@ -1639,7 +1629,6 @@ static void pci_devices_present_work(struct work_struct *work) spin_unlock_irqrestore(&hbus->device_list_lock, flags);

if (!dr) { - up(&hbus->enum_sem); put_hvpcibus(hbus); return; } @@ -1726,7 +1715,6 @@ static void pci_devices_present_work(struct work_struct *work) break; }

- up(&hbus->enum_sem); put_hvpcibus(hbus); kfree(dr); } @@ -2460,7 +2448,6 @@ static int hv_pci_probe(struct hv_device *hdev, spin_lock_init(&hbus->config_lock); spin_lock_init(&hbus->device_list_lock); spin_lock_init(&hbus->retarget_msi_interrupt_lock); - sema_init(&hbus->enum_sem, 1); init_completion(&hbus->remove_event); hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0, hbus->sysdata.domain);