* [PATCH v7 1/4] PCI: pciehp: Use per-slot workqueues to avoid deadlock
2013-01-13 23:27 [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Bjorn Helgaas
@ 2013-01-13 23:27 ` Bjorn Helgaas
2013-01-13 23:27 ` [PATCH v7 2/4] PCI: shpchp: Make shpchp_wq non-ordered Bjorn Helgaas
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Bjorn Helgaas @ 2013-01-13 23:27 UTC (permalink / raw)
To: Yijing Wang, linux-pci
Cc: linux-kernel, stable, Daniel J Blueman, Kenji Kaneshige,
Tejun Heo, Yinghai Lu, Jiang Liu
From: Yijing Wang <wangyijing@huawei.com>
When we have a hotplug-capable PCIe port with a second hotplug-capable
PCIe port below it, removing the device below the upstream port causes
a deadlock.
The deadlock happens because we use the pciehp_wq workqueue to run
pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices
below the upstream port. When we remove the downstream PCIe port, we call
pciehp_remove(), the pciehp driver's .remove() method. That calls
flush_workqueue(pciehp_wq), which deadlocks because the
pciehp_power_thread() work item is still running.
This patch avoids the deadlock by creating a workqueue for every PCIe port
and removing the single shared workqueue.
Here's the call path that leads to the deadlock:
pciehp_queue_pushbutton_work
queue_work(pciehp_wq) # queue pciehp_power_thread
...
pciehp_power_thread
pciehp_disable_slot
remove_board
pciehp_unconfigure_device
pci_stop_and_remove_bus_device
...
pciehp_remove # pciehp driver .remove method
pciehp_release_ctrl
pcie_cleanup_slot
flush_workqueue(pciehp_wq)
This is fairly urgent because it can be caused by simply unplugging a
Thunderbolt adapter, as reported by Daniel below.
[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman <daniel@quora.org>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
---
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@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
@@ -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);
}
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v7 2/4] PCI: shpchp: Make shpchp_wq non-ordered
2013-01-13 23:27 [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Bjorn Helgaas
2013-01-13 23:27 ` [PATCH v7 1/4] PCI: pciehp: Use per-slot workqueues to avoid deadlock Bjorn Helgaas
@ 2013-01-13 23:27 ` Bjorn Helgaas
2013-01-14 16:49 ` Tejun Heo
2013-01-13 23:27 ` [PATCH v7 3/4] PCI: shpchp: Handle push button event asynchronously Bjorn Helgaas
` (2 subsequent siblings)
4 siblings, 1 reply; 7+ messages in thread
From: Bjorn Helgaas @ 2013-01-13 23:27 UTC (permalink / raw)
To: Yijing Wang, linux-pci
Cc: linux-kernel, Daniel J Blueman, Kenji Kaneshige, Tejun Heo,
Yinghai Lu, Jiang Liu
e24dcbef93 ("shpchp: update workqueue usage") was described as adding
non-ordered shpchp_wq, but it actually made it an *ordered* workqueue.
This patch changes shpchp_wq to be non-ordered, as described in the
e24dcbef93 commit log and as was done for pciehp by a827ea307b ("pciehp:
update workqueue usage").
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Tejun Heo <tj@kernel.org>
---
drivers/pci/hotplug/shpchp_core.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index b6de307..59ca86c 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -366,7 +366,7 @@ static int __init shpcd_init(void)
{
int retval = 0;
- shpchp_wq = alloc_ordered_workqueue("shpchp", 0);
+ shpchp_wq = alloc_workqueue("shpchp", 0, 0);
if (!shpchp_wq)
return -ENOMEM;
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v7 2/4] PCI: shpchp: Make shpchp_wq non-ordered
2013-01-13 23:27 ` [PATCH v7 2/4] PCI: shpchp: Make shpchp_wq non-ordered Bjorn Helgaas
@ 2013-01-14 16:49 ` Tejun Heo
0 siblings, 0 replies; 7+ messages in thread
From: Tejun Heo @ 2013-01-14 16:49 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Yijing Wang, linux-pci, linux-kernel, Daniel J Blueman,
Kenji Kaneshige, Yinghai Lu, Jiang Liu
Hello,
On Sun, Jan 13, 2013 at 04:27:43PM -0700, Bjorn Helgaas wrote:
> e24dcbef93 ("shpchp: update workqueue usage") was described as adding
> non-ordered shpchp_wq, but it actually made it an *ordered* workqueue.
>
> This patch changes shpchp_wq to be non-ordered, as described in the
> e24dcbef93 commit log and as was done for pciehp by a827ea307b ("pciehp:
> update workqueue usage").
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> CC: Tejun Heo <tj@kernel.org>
Yeap, my mistake.
Acked-by: Tejun Heo <tj@kernel.org>
Thanks!
--
tejun
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v7 3/4] PCI: shpchp: Handle push button event asynchronously
2013-01-13 23:27 [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Bjorn Helgaas
2013-01-13 23:27 ` [PATCH v7 1/4] PCI: pciehp: Use per-slot workqueues to avoid deadlock Bjorn Helgaas
2013-01-13 23:27 ` [PATCH v7 2/4] PCI: shpchp: Make shpchp_wq non-ordered Bjorn Helgaas
@ 2013-01-13 23:27 ` Bjorn Helgaas
2013-01-13 23:27 ` [PATCH v7 4/4] PCI: shpchp: Use per-slot workqueues to avoid deadlock Bjorn Helgaas
2013-01-14 1:30 ` [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Yijing Wang
4 siblings, 0 replies; 7+ messages in thread
From: Bjorn Helgaas @ 2013-01-13 23:27 UTC (permalink / raw)
To: Yijing Wang, linux-pci
Cc: linux-kernel, Daniel J Blueman, Kenji Kaneshige, Tejun Heo,
Yinghai Lu, Jiang Liu
Use non-ordered workqueue for attention button events.
Attention button events on each slot can be handled asynchronously. So
we should use non-ordered workqueue. This patch also removes ordered
workqueue in shpchp as a result.
486b10b9f4 ("PCI: pciehp: Handle push button event asynchronously") made
the same change to pciehp. I split this out from a patch by Yijing Wang
<wangyijing@huawei.com> so we fix one thing at a time and to make the
shpchp history correspond more closely with the pciehp history.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
---
drivers/pci/hotplug/shpchp.h | 1 -
drivers/pci/hotplug/shpchp_core.c | 10 ----------
drivers/pci/hotplug/shpchp_ctrl.c | 2 +-
3 files changed, 1 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index ca64932..1b69d95 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -47,7 +47,6 @@ 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 { \
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index 59ca86c..3774e0d 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -40,7 +40,6 @@ 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@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
@@ -181,7 +180,6 @@ void cleanup_slots(struct controller *ctrl)
list_del(&slot->slot_list);
cancel_delayed_work(&slot->work);
flush_workqueue(shpchp_wq);
- flush_workqueue(shpchp_ordered_wq);
pci_hp_deregister(slot->hotplug_slot);
}
}
@@ -370,17 +368,10 @@ static int __init shpcd_init(void)
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;
@@ -390,7 +381,6 @@ 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..fd2cae9 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -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(shpchp_wq, &info->work);
out:
mutex_unlock(&p_slot->lock);
}
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v7 4/4] PCI: shpchp: Use per-slot workqueues to avoid deadlock
2013-01-13 23:27 [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Bjorn Helgaas
` (2 preceding siblings ...)
2013-01-13 23:27 ` [PATCH v7 3/4] PCI: shpchp: Handle push button event asynchronously Bjorn Helgaas
@ 2013-01-13 23:27 ` Bjorn Helgaas
2013-01-14 1:30 ` [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Yijing Wang
4 siblings, 0 replies; 7+ messages in thread
From: Bjorn Helgaas @ 2013-01-13 23:27 UTC (permalink / raw)
To: Yijing Wang, linux-pci
Cc: linux-kernel, stable, Daniel J Blueman, Kenji Kaneshige,
Tejun Heo, Yinghai Lu, Jiang Liu
When we have an SHPC-capable bridge with a second SHPC-capable bridge
below it, pushing the upstream bridge's attention button causes a
deadlock.
The deadlock happens because we use the shpchp_wq workqueue to run
shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove
devices below the upstream bridge. When we remove the downstream bridge,
we call shpc_remove(), the shpchp driver's .remove() method. That calls
flush_workqueue(shpchp_wq), which deadlocks because the
shpchp_pushbutton_thread() work item is still running.
This patch avoids the deadlock by creating a workqueue for every slot
and removing the single shared workqueue.
Here's the call path that leads to the deadlock:
shpchp_queue_pushbutton_work
queue_work(shpchp_wq) # shpchp_pushbutton_thread
...
shpchp_pushbutton_thread
shpchp_disable_slot
remove_board
shpchp_unconfigure_device
pci_stop_and_remove_bus_device
...
shpc_remove # shpchp driver .remove method
hpc_release_ctlr
cleanup_slots
flush_workqueue(shpchp_wq)
This change is based on code inspection, since we don't have hardware
with this topology.
Based-on-patch-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
---
drivers/pci/hotplug/shpchp.h | 2 +-
drivers/pci/hotplug/shpchp_core.c | 26 ++++++++++++++------------
drivers/pci/hotplug/shpchp_ctrl.c | 6 +++---
3 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index 1b69d95..b849f995 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -46,7 +46,6 @@
extern bool shpchp_poll_mode;
extern int shpchp_poll_time;
extern bool shpchp_debug;
-extern struct workqueue_struct *shpchp_wq;
#define dbg(format, arg...) \
do { \
@@ -90,6 +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 3774e0d..3100c52 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -39,7 +39,6 @@
bool shpchp_debug;
bool shpchp_poll_mode;
int shpchp_poll_time;
-struct workqueue_struct *shpchp_wq;
#define DRIVER_VERSION "0.4"
#define DRIVER_AUTHOR "Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
@@ -128,6 +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);
@@ -147,7 +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);
@@ -159,6 +166,8 @@ static int init_slots(struct controller *ctrl)
}
return 0;
+error_slotwq:
+ destroy_workqueue(slot->wq);
error_info:
kfree(info);
error_hpslot:
@@ -179,7 +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);
+ destroy_workqueue(slot->wq);
pci_hp_deregister(slot->hotplug_slot);
}
}
@@ -362,18 +371,12 @@ static struct pci_driver shpc_driver = {
static int __init shpcd_init(void)
{
- int retval = 0;
-
- shpchp_wq = alloc_workqueue("shpchp", 0, 0);
- if (!shpchp_wq)
- return -ENOMEM;
+ int retval;
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_wq);
- }
+
return retval;
}
@@ -381,7 +384,6 @@ static void __exit shpcd_cleanup(void)
{
dbg("unload_shpchpd()\n");
pci_unregister_driver(&shpc_driver);
- 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 fd2cae9..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_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:
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes
2013-01-13 23:27 [PATCH v7 0/4] PCI: pciehp, shpchp deadlock fixes Bjorn Helgaas
` (3 preceding siblings ...)
2013-01-13 23:27 ` [PATCH v7 4/4] PCI: shpchp: Use per-slot workqueues to avoid deadlock Bjorn Helgaas
@ 2013-01-14 1:30 ` Yijing Wang
4 siblings, 0 replies; 7+ messages in thread
From: Yijing Wang @ 2013-01-14 1:30 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: linux-pci, linux-kernel, Daniel J Blueman, Kenji Kaneshige,
Tejun Heo, Yinghai Lu, Jiang Liu
On 2013/1/14 7:27, Bjorn Helgaas wrote:
> This is v7 of Yijing Wang's pciehp deadlock fix. Here's the history of
> previous postings:
>
> RFC Oct 31 2012
> v2 Nov 9 2012 use slot name, not device name
> v3 Nov 12 2012 create workqueues in pcie_init_slot(), pciehp-%u format
> v4 Nov 13 2012 use alloc_workqueue(name, 0, 0) again
> v5 Jan 9 2013 fix similar problem in shpchp
> v6 Jan 10 2013 add pciehp backtrace from Daniel
>
> This v7 series is functionally identical to v6. In v7, I split the single
> shpchp patch into three:
>
> PCI: shpchp: Make shpchp_wq non-ordered
> PCI: shpchp: Handle push button event asynchronously
> PCI: shpchp: Use per-slot workqueues to avoid deadlock
>
Nice, split the single patch into three will make the log clearer about the
code changes.
> The first fixes what appears to be an error in e24dcbef93 ("shpchp: update
> workqueue usage"). I split this out so Tejun could easily review it by itself.
>
> I split the second out because it corresponds to a pciehp bugfix, 486b10b9f4
> ("PCI: pciehp: Handle push button event asynchronously"), that also affects
> shpchp.
>
> The "PCI: shpchp: Use per-slot workqueues to avoid deadlock" that remains
> then corresponds exactly to Yijing's original pciehp deadlock fix.
>
> I also rewrote the changelogs.
>
> I propose to push the entire series for inclusion in v3.8, since it
> fixes an easy-to-cause deadlock with Thunderbolt adapters.
>
> ---
>
> Bjorn Helgaas (3):
> PCI: shpchp: Make shpchp_wq non-ordered
> PCI: shpchp: Handle push button event asynchronously
> PCI: shpchp: Use per-slot workqueues to avoid deadlock
>
> Yijing Wang (1):
> PCI: pciehp: Use per-slot workqueues to avoid deadlock
>
>
> 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 ++++++++++-
> drivers/pci/hotplug/shpchp.h | 3 +--
> drivers/pci/hotplug/shpchp_core.c | 36 ++++++++++++++----------------------
> drivers/pci/hotplug/shpchp_ctrl.c | 6 +++---
> 7 files changed, 35 insertions(+), 42 deletions(-)
>
>
--
Thanks!
Yijing
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