Currently, pciehp use global pciehp_wq to handle hotplug event from hardware.
Hot remove path will be blocked if a hotplug slot connected a IO-BOX(composed of PCIe
Switch and some slots which support hotplug). Because The hot removed work was queued
into pciehp_wq. But in the hot-remove path, pciehp driver would flush pciehp_wq when
the pcie port(support pciehp) was removed. In this case the hot-remove path blocked.
This patch remove the global pciehp_wq and create a new workqueue for every slot to
avoid above problem.
call path:
1. Hot-removal request comes to slot A(eg. 0000:40:07.0 as bellow)
2. Pciehp driver queue hot-remove work into global workqueue "pciehp_wq"
3. Hot-remove work call pci_stop_and_remove_bus_device() to remove child devices.
4. Unregister and remove Pcie port device slot B(eg. 0000:47:15.0).
5. To remove pcie port device, flush_workqueue(pciehp_wq) will be called.
6. Deaklock <== hot-removal work is in progress.
+-07.0-[0000:46-4f]----00.0-[0000:47-4f]--+-04.0-[0000:48-49]----00.0-[0000:49]--
|(slot A) +-08.0-[0000:4a]--
| +-09.0-[0000:4b]--
| +-10.0-[0000:4c]--
| +-11.0-[0000:4d]--
| +-14.0-[0000:4e]--
| \-15.0-[0000:4f]--+-00.0 Intel Corporation 82576 Gigabit Network Connection
| (slot B) \-00.1 Intel Corporation 82576 Gigabit Network Connection
The syslog reported by Daniel J Blueman:
powering on due to button press.
pciehp 0000:09:00.0:pcie24: Link Training Error occurs
pciehp 0000:09:00.0:pcie24: Failed to check link status
INFO: task kworker/0:1:52 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:1 D ffff880265893090 0 52 2 0x00000000
ffff8802655456f8 0000000000000046 ffffffff81a21a60 ffff880265545fd8
0000000000004000 ffff880265545fd8 ffff880265892bb0 ffff880265adc8d0
000000000000059e 0000000000000082 ffff880265545668 ffffffff810415aa
Call Trace:
[<ffffffff810415aa>] ? console_unlock+0x1fa/0x4a0
[<ffffffff8108d16d>] ? trace_hardirqs_off+0xd/0x10
[<ffffffff81041b19>] ? vprintk_emit+0x1c9/0x510
[<ffffffff81558db4>] schedule+0x24/0x70
[<ffffffff8155653c>] schedule_timeout+0x19c/0x1e0
[<ffffffff81558c43>] wait_for_common+0xe3/0x180
[<ffffffff8105adc1>] ? flush_workqueue+0x111/0x4d0
[<ffffffff81071140>] ? try_to_wake_up+0x2d0/0x2d0
[<ffffffff81558d88>] wait_for_completion+0x18/0x20
[<ffffffff8105ae86>] flush_workqueue+0x1d6/0x4d0
[<ffffffff8105acb0>] ? flush_workqueue_prep_cwqs+0x200/0x200
[<ffffffff8125e909>] pciehp_release_ctrl+0x39/0x90
[<ffffffff8125b945>] pciehp_remove+0x25/0x30
[<ffffffff81255bf2>] pcie_port_remove_service+0x52/0x70
[<ffffffff81306a27>] __device_release_driver+0x77/0xe0
[<ffffffff81306ab9>] device_release_driver+0x29/0x40
[<ffffffff813064b1>] bus_remove_device+0xf1/0x140
[<ffffffff81303fe7>] device_del+0x127/0x1c0
[<ffffffff81255d70>] ? resume_iter+0x40/0x40
[<ffffffff81304091>] device_unregister+0x11/0x20
[<ffffffff81255da5>] remove_iter+0x35/0x40
[<ffffffff81302eb6>] device_for_each_child+0x36/0x70
[<ffffffff81256341>] pcie_port_device_remove+0x21/0x40
[<ffffffff81256588>] pcie_portdrv_remove+0x28/0x50
[<ffffffff8124a821>] pci_device_remove+0x41/0xc0
[<ffffffff81306a27>] __device_release_driver+0x77/0xe0
[<ffffffff81306ab9>] device_release_driver+0x29/0x40
[<ffffffff813064b1>] bus_remove_device+0xf1/0x140
[<ffffffff81303fe7>] device_del+0x127/0x1c0
[<ffffffff81304091>] device_unregister+0x11/0x20
[<ffffffff8124566c>] pci_stop_bus_device+0x8c/0xa0
[<ffffffff81245615>] pci_stop_bus_device+0x35/0xa0
[<ffffffff81245811>] pci_stop_and_remove_bus_device+0x11/0x20
[<ffffffff8125cc91>] pciehp_unconfigure_device+0x91/0x190
[<ffffffff8125c76d>] ? pciehp_power_thread+0x2d/0x110
[<ffffffff8125c591>] pciehp_disable_slot+0x71/0x220
[<ffffffff8125c826>] pciehp_power_thread+0xe6/0x110
[<ffffffff8105d203>] process_one_work+0x193/0x550
[<ffffffff8105d1a1>] ? process_one_work+0x131/0x550
[<ffffffff8125c740>] ? pciehp_disable_slot+0x220/0x220
[<ffffffff8105d96d>] worker_thread+0x15d/0x400
[<ffffffff8109213d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8105d810>] ? rescuer_thread+0x210/0x210
[<ffffffff81062bd6>] kthread+0xd6/0xe0
[<ffffffff8155a18b>] ? _raw_spin_unlock_irq+0x2b/0x50
[<ffffffff81062b00>] ? __init_kthread_worker+0x70/0x70
[<ffffffff8155ae6c>] ret_from_fork+0x7c/0xb0
[<ffffffff81062b00>] ? __init_kthread_worker+0x70/0x70
Reported-by: Daniel J Blueman <daniel@xxxxxxxxx>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/pci/hotplug/pciehp.h | 2 +-
drivers/pci/hotplug/pciehp_core.c | 11 ++---------
drivers/pci/hotplug/pciehp_ctrl.c | 8 ++++----
drivers/pci/hotplug/pciehp_hpc.c | 11 ++++++++++-
4 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 26ffd3e..2c113de 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -44,7 +44,6 @@ extern bool pciehp_poll_mode;
extern int pciehp_poll_time;
extern bool pciehp_debug;
extern bool pciehp_force;
-extern struct workqueue_struct *pciehp_wq;
#define dbg(format, arg...) \
do { \
@@ -78,6 +77,7 @@ struct slot {
struct hotplug_slot *hotplug_slot;
struct delayed_work work; /* work for button event */
struct mutex lock;
+ struct workqueue_struct *wq;
};
struct event_info {
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 916bf4f..939bd1d 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -42,7 +42,6 @@ bool pciehp_debug;
bool pciehp_poll_mode;
int pciehp_poll_time;
bool pciehp_force;
-struct workqueue_struct *pciehp_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>"
@@ -340,18 +339,13 @@ static int __init pcied_init(void)
{
int retval = 0;
- pciehp_wq = alloc_workqueue("pciehp", 0, 0);
- if (!pciehp_wq)
- return -ENOMEM;
-
pciehp_firmware_init();
retval = pcie_port_service_register(&hpdriver_portdrv);
dbg("pcie_port_service_register = %d\n", retval);
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
- if (retval) {
- destroy_workqueue(pciehp_wq);
+ if (retval)
dbg("Failure to register service\n");
- }
+
return retval;
}
@@ -359,7 +353,6 @@ static void __exit pcied_cleanup(void)
{
dbg("unload_pciehpd()\n");
pcie_port_service_unregister(&hpdriver_portdrv);
- destroy_workqueue(pciehp_wq);
info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
}
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index 27f4429..38f0186 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -49,7 +49,7 @@ 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(pciehp_wq, &info->work);
+ queue_work(p_slot->wq, &info->work);
return 0;
}
@@ -344,7 +344,7 @@ void pciehp_queue_pushbutton_work(struct work_struct *work)
kfree(info);
goto out;
}
- queue_work(pciehp_wq, &info->work);
+ queue_work(p_slot->wq, &info->work);
out:
mutex_unlock(&p_slot->lock);
}
@@ -377,7 +377,7 @@ static void handle_button_press_event(struct slot *p_slot)
if (ATTN_LED(ctrl))
pciehp_set_attention_status(p_slot, 0);
- queue_delayed_work(pciehp_wq, &p_slot->work, 5*HZ);
+ queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
break;
case BLINKINGOFF_STATE:
case BLINKINGON_STATE:
@@ -439,7 +439,7 @@ static void handle_surprise_event(struct slot *p_slot)
else
p_slot->state = POWERON_STATE;
- queue_work(pciehp_wq, &info->work);
+ queue_work(p_slot->wq, &info->work);
}
static void interrupt_event_handler(struct work_struct *work)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 13b2eaf..5127f3f 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -773,23 +773,32 @@ static void pcie_shutdown_notification(struct controller *ctrl)
static int pcie_init_slot(struct controller *ctrl)
{
struct slot *slot;
+ char name[32];
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
return -ENOMEM;
+ snprintf(name, sizeof(name), "pciehp-%u", PSN(ctrl));
+ slot->wq = alloc_workqueue(name, 0, 0);
+ if (!slot->wq)
+ goto abort;
+
slot->ctrl = ctrl;
mutex_init(&slot->lock);
INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
ctrl->slot = slot;
return 0;
+abort:
+ kfree(slot);
+ return -ENOMEM;
}
static void pcie_cleanup_slot(struct controller *ctrl)
{
struct slot *slot = ctrl->slot;
cancel_delayed_work(&slot->work);
- flush_workqueue(pciehp_wq);
+ destroy_workqueue(slot->wq);
kfree(slot);
}
--
1.7.1
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