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 <[email protected]> Reviewed-by: Kenji Kaneshige <[email protected]> Signed-off-by: Yijing Wang <[email protected]> Cc: [email protected] --- 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 <[email protected]>, Greg Kroah-Hartman <[email protected]>, Dely Sy <[email protected]>" @@ -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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
