Use PCI hotplug lock to serialize hotplug operations triggered by the
shpchp driver.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/pci/hotplug/shpchp.h | 2 ++
drivers/pci/hotplug/shpchp_core.c | 3 ++-
drivers/pci/hotplug/shpchp_ctrl.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 36 insertions(+), 1 deletions(-)
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index 6691dc4..07f3b2d 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -157,6 +157,7 @@ struct controller {
#define BLINKINGOFF_STATE 2
#define POWERON_STATE 3
#define POWEROFF_STATE 4
+#define SHUTDOWN_STATE 5
/* Error messages */
#define INTERLOCK_OPEN 0x00000002
@@ -179,6 +180,7 @@ extern u8 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl);
extern u8 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl);
extern int shpchp_configure_device(struct slot *p_slot);
extern int shpchp_unconfigure_device(struct slot *p_slot);
+extern void shpchp_shutdown_slot(struct slot *slot);
extern void cleanup_slots(struct controller *ctrl);
extern void shpchp_queue_pushbutton_work(struct work_struct *work);
extern int shpc_init( struct controller *ctrl, struct pci_dev *pdev);
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index 19762b3..71cc5f2 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -172,10 +172,11 @@ void cleanup_slots(struct controller *ctrl)
list_for_each_safe(tmp, next, &ctrl->slot_list) {
slot = list_entry(tmp, struct slot, slot_list);
- list_del(&slot->slot_list);
flush_workqueue(shpchp_wq);
cancel_delayed_work_sync(&slot->work);
+ shpchp_shutdown_slot(slot);
flush_workqueue(shpchp_ordered_wq);
+ list_del(&slot->slot_list);
pci_hp_deregister(slot->hotplug_slot);
}
}
diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index b00b09b..7b8e3a6 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -31,6 +31,7 @@
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
+#include <linux/delay.h>
#include <linux/pci.h>
#include "../pci.h"
#include "shpchp.h"
@@ -406,6 +407,18 @@ static void shpchp_pushbutton_thread(struct work_struct *work)
struct pushbutton_work_info *info =
container_of(work, struct pushbutton_work_info, work);
struct slot *p_slot = info->p_slot;
+ bool shutdown;
+
+ /* Break possible deadlock by using pci_hotplug_try_enter() */
+ while (!pci_hotplug_try_enter()) {
+ mutex_lock(&p_slot->lock);
+ shutdown = p_slot->state == SHUTDOWN_STATE;
+ mutex_unlock(&p_slot->lock);
+ if (shutdown)
+ goto out;
+ else
+ mdelay(1);
+ }
mutex_lock(&p_slot->lock);
switch (p_slot->state) {
@@ -427,6 +440,9 @@ static void shpchp_pushbutton_thread(struct work_struct *work)
}
mutex_unlock(&p_slot->lock);
+ pci_hotplug_exit();
+
+out:
kfree(info);
}
@@ -729,3 +745,19 @@ int shpchp_sysfs_disable_slot(struct slot *p_slot)
return retval;
}
+
+void shpchp_shutdown_slot(struct slot *slot)
+{
+ u8 getstatus;
+
+ mutex_lock(&slot->lock);
+ slot->state = SHUTDOWN_STATE;
+ mutex_unlock(&slot->lock);
+
+ slot->hpc_ops->set_attention_status(slot, 0);
+ slot->hpc_ops->get_power_status(slot, &getstatus);
+ if (getstatus)
+ slot->hpc_ops->green_led_on(slot);
+ else
+ slot->hpc_ops->green_led_off(slot);
+}
--
1.7.5.4
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