remove the global shpchp_wq,shpchp_ordered_wq and create a new workqueue
for every slot to avoid deadlock when hot remove a pci iobox(which is
slot--connected---slot).
call path:
button press
shpc_isr(interrupt handler)
shpchp_handle_attention_button
queue_interrupt_event
queue_work "interrupt_event_handler" into "shpchp_wq"
interrupt_event_handler
handle_button_press_event
queue_delayed_work "shpchp_queue_pushbutton_work" into "shpchp_wq"
queue_work "shpchp_pushbutton_thread" into "shpchp_ordered_wq"
shpchp_pushbutton_thread
shpchp_disable_slot
pci_stop_and_remove_bus_device
......
shpc_remove()
hpc_release_ctlr
flush_workqueue(shpchp_wq);
flush_workqueue(shpchp_ordered_wq);
In this call path, flush_workqueue task will hang, because shpchp_ordered_wq is running.
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
---
drivers/pci/hotplug/shpchp.h | 3 +--
drivers/pci/hotplug/shpchp_core.c | 34 +++++++++++++---------------------
drivers/pci/hotplug/shpchp_ctrl.c | 6 +++---
3 files changed, 17 insertions(+), 26 deletions(-)
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index ca64932..b849f99 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -46,8 +46,6 @@
extern bool shpchp_poll_mode;
extern int shpchp_poll_time;
extern bool shpchp_debug;
-extern struct workqueue_struct *shpchp_wq;
-extern struct workqueue_struct *shpchp_ordered_wq;
#define dbg(format, arg...) \
do { \
@@ -91,6 +89,7 @@ struct slot {
struct list_head slot_list;
struct delayed_work work; /* work for button event */
struct mutex lock;
+ struct workqueue_struct *wq;
u8 hp_slot;
};
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index b6de307..01d39cc 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -39,8 +39,6 @@
bool shpchp_debug;
bool shpchp_poll_mode;
int shpchp_poll_time;
-struct workqueue_struct *shpchp_wq;
-struct workqueue_struct *shpchp_ordered_wq;
#define DRIVER_VERSION "0.4"
#define DRIVER_AUTHOR "Dan Zink <dan.zink@xxxxxxxxxx>, Greg Kroah-Hartman <greg@xxxxxxxxx>, Dely Sy <dely.l.sy@xxxxxxxxx>"
@@ -129,6 +127,14 @@ static int init_slots(struct controller *ctrl)
slot->device = ctrl->slot_device_offset + i;
slot->hpc_ops = ctrl->hpc_ops;
slot->number = ctrl->first_slot + (ctrl->slot_num_inc * i);
+
+ snprintf(name, sizeof(name), "shpchp-%d", slot->number);
+ slot->wq = alloc_workqueue(name, 0, 0);
+ if (!slot->wq) {
+ retval = -ENOMEM;
+ goto error_info;
+ }
+
mutex_init(&slot->lock);
INIT_DELAYED_WORK(&slot->work, shpchp_queue_pushbutton_work);
@@ -148,7 +154,7 @@ static int init_slots(struct controller *ctrl)
if (retval) {
ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
retval);
- goto error_info;
+ goto error_slotwq;
}
get_power_status(hotplug_slot, &info->power_status);
@@ -160,6 +166,8 @@ static int init_slots(struct controller *ctrl)
}
return 0;
+error_slotwq:
+ destroy_workqueue(slot->wq);
error_info:
kfree(info);
error_hpslot:
@@ -180,8 +188,7 @@ void cleanup_slots(struct controller *ctrl)
slot = list_entry(tmp, struct slot, slot_list);
list_del(&slot->slot_list);
cancel_delayed_work(&slot->work);
- flush_workqueue(shpchp_wq);
- flush_workqueue(shpchp_ordered_wq);
+ destroy_workqueue(slot->wq);
pci_hp_deregister(slot->hotplug_slot);
}
}
@@ -366,23 +373,10 @@ static int __init shpcd_init(void)
{
int retval = 0;
- shpchp_wq = alloc_ordered_workqueue("shpchp", 0);
- if (!shpchp_wq)
- return -ENOMEM;
-
- shpchp_ordered_wq = alloc_ordered_workqueue("shpchp_ordered", 0);
- if (!shpchp_ordered_wq) {
- destroy_workqueue(shpchp_wq);
- return -ENOMEM;
- }
-
retval = pci_register_driver(&shpc_driver);
dbg("%s: pci_register_driver = %d\n", __func__, retval);
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
- if (retval) {
- destroy_workqueue(shpchp_ordered_wq);
- destroy_workqueue(shpchp_wq);
- }
+
return retval;
}
@@ -390,8 +384,6 @@ static void __exit shpcd_cleanup(void)
{
dbg("unload_shpchpd()\n");
pci_unregister_driver(&shpc_driver);
- destroy_workqueue(shpchp_ordered_wq);
- destroy_workqueue(shpchp_wq);
info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
}
diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index f9b5a52..5849927 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -51,7 +51,7 @@ static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
info->p_slot = p_slot;
INIT_WORK(&info->work, interrupt_event_handler);
- queue_work(shpchp_wq, &info->work);
+ queue_work(p_slot->wq, &info->work);
return 0;
}
@@ -453,7 +453,7 @@ void shpchp_queue_pushbutton_work(struct work_struct *work)
kfree(info);
goto out;
}
- queue_work(shpchp_ordered_wq, &info->work);
+ queue_work(p_slot->wq, &info->work);
out:
mutex_unlock(&p_slot->lock);
}
@@ -501,7 +501,7 @@ static void handle_button_press_event(struct slot *p_slot)
p_slot->hpc_ops->green_led_blink(p_slot);
p_slot->hpc_ops->set_attention_status(p_slot, 0);
- queue_delayed_work(shpchp_wq, &p_slot->work, 5*HZ);
+ queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
break;
case BLINKINGOFF_STATE:
case BLINKINGON_STATE:
--
1.7.1
--
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