- Add pciehp_disconnect_work() , this function is used using schedule_work from
pciehp_isr allowing us to not wait in pciehp_isr()
- pciehp_disconnect_work() is scheduled only if the card is not detected (PDS
bit = 0).
The PDS bit can be used to differentiate between a safe and surprise
removal.
Signed-off-by: Abhin Parekadan Jose <[email protected]>
---
drivers/pci/hotplug/pciehp_hpc.c | 47 ++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 4c62140a3cb4..69ed6b060e9d 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -620,6 +620,40 @@ static void pciehp_ignore_link_change(struct controller
*ctrl,
up_read(&ctrl->reset_lock);
}
+/*
+ * Workaround to not wait in the isr.
+ */
+static void pciehp_disconnect_work(struct work_struct *work)
+{
+ struct controller *ctrl = container_of(work, struct controller,
+ disconnect_work);
+ struct pci_dev *pdev = ctrl_dev(ctrl);
+ int events;
+
+ events = atomic_read(&ctrl->pending_events);
+
+ /*
+ * Ignore Link Down/Up events caused by Downstream Port Containment
+ * if recovery succeeded, or caused by Secondary Bus Reset,
+ * suspend to D3cold, firmware update, FPGA reconfiguration, etc.
+ */
+ if ((events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) &&
+ (pci_dpc_recovered(pdev) || pci_hp_spurious_link_change(pdev)) &&
+ ctrl->state == ON_STATE) {
+ // Ignore the link change events and return to normal operation.
+ // Could also wait here if needed.
+ return;
+ }
+
+ struct pci_bus *bus = ctrl->pcie->port->subordinate;
+
+ /* the card may have returned. */
+ if (!bus || pciehp_card_present(ctrl) != 0)
+ return;
+
+ pci_walk_bus(bus, pci_dev_set_disconnected, NULL);
+}
+
static irqreturn_t pciehp_isr(int irq, void *dev_id)
{
struct controller *ctrl = (struct controller *)dev_id;
@@ -722,6 +756,17 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
/* Save pending events for consumption by IRQ thread. */
atomic_or(events, &ctrl->pending_events);
+
+ // presence change events
+ if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) {
+ // Get PDS bit to determine if card is present or not
+ int present = pciehp_card_present(ctrl);
+ if (!present) { // for sure the card is not present
+ schedule_work(&ctrl->disconnect_work);
+ // After this we are no longer in isr and can wait.
+ }
+ }
+
return IRQ_WAKE_THREAD;
}
@@ -1036,6 +1081,7 @@ struct controller *pcie_init(struct pcie_device *dev)
init_waitqueue_head(&ctrl->requester);
init_waitqueue_head(&ctrl->queue);
INIT_DELAYED_WORK(&ctrl->button_work, pciehp_queue_pushbutton_work);
+ INIT_WORK(&ctrl->disconnect_work, pciehp_disconnect_work);
dbg_ctrl(ctrl);
down_read(&pci_bus_sem);
@@ -1096,6 +1142,7 @@ struct controller *pcie_init(struct pcie_device *dev)
void pciehp_release_ctrl(struct controller *ctrl)
{
cancel_delayed_work_sync(&ctrl->button_work);
+ cancel_work_sync(&ctrl->disconnect_work);
kfree(ctrl);
}
--
2.51.1
