Currently, if very fast hotplug removal and insertion event comes
as following
[ 608.823412] pciehp 0000:00:1c.1:pcie04: Card not present on Slot(1)
[ 608.835249] pciehp 0000:00:1c.1:pcie04: Card present on Slot(1)
In this case following scenario happens,
While removal:
pcie_isr() -> pciehp_queue_interrupt_event() -> triggers queue_work().
work invokes interrupt_event_handler() -> case INT_PRESENCE_OFF
and calls handle_surprise_event().
handle_surprise_event() again calls pciehp_get_adapter_status()
and reads slot status which might have been changed
already due to PCI_EXP_SLTSTA_PDC event for hotplug insertion
has happened. So it queues, ENABLE_REQ for both removal
and insertion interrupt based on latest slot status.
In this case, PCIe device can not be hot-add again because
it was never removed due to which device can not get enabled.
handle_surprise_event() can be removed and pciehp_queue_power_work()
can be directly triggered based on INT_PRESENCE_ON and INT_PRESENCE_OFF
from the switch case exist in interrupt_event_hanlder().
The patch ensures the pciehp_queue_power_work() processes
presence detect change for removal and insertion correctly.
Signed-off-by: Mayurkumar Patel <mayurkumar.patel@xxxxxxxxx>
Acked-by: Rajat Jain <rajatxjain@xxxxxxxxx>
---
Resending the patch with another patch which has pcie_isr() correct
event handling proposal
drivers/pci/hotplug/pciehp_ctrl.c | 18 ++----------------
1 file changed, 2 insertions(+), 16 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index 880978b..87c5bea 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -301,20 +301,6 @@ static void handle_button_press_event(struct slot *p_slot)
/*
* Note: This function must be called with slot->lock held
*/
-static void handle_surprise_event(struct slot *p_slot)
-{
- u8 getstatus;
-
- pciehp_get_adapter_status(p_slot, &getstatus);
- if (!getstatus)
- pciehp_queue_power_work(p_slot, DISABLE_REQ);
- else
- pciehp_queue_power_work(p_slot, ENABLE_REQ);
-}
-
-/*
- * Note: This function must be called with slot->lock held
- */
static void handle_link_event(struct slot *p_slot, u32 event)
{
struct controller *ctrl = p_slot->ctrl;
@@ -377,14 +363,14 @@ static void interrupt_event_handler(struct work_struct *work)
pciehp_green_led_off(p_slot);
break;
case INT_PRESENCE_ON:
- handle_surprise_event(p_slot);
+ pciehp_queue_power_work(p_slot, ENABLE_REQ);
break;
case INT_PRESENCE_OFF:
/*
* Regardless of surprise capability, we need to
* definitely remove a card that has been pulled out!
*/
- handle_surprise_event(p_slot);
+ pciehp_queue_power_work(p_slot, DISABLE_REQ);
break;
case INT_LINK_UP:
case INT_LINK_DOWN:
--
1.7.9.5
Intel Deutschland GmbH
Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Christin Eisenschmid, Christian Lamprechter
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
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