cnss2: Unregister host driver during PCI remove

CNSS2 registers as both platform and PCI driver. PCI
device can be removed via sysfs exposed by kernel during
PCI device creation. When PCI device gets removed, CNSS
PCI remove ops gets called. In cnss_pci_remove, unregister
host driver and shutdown WLAN chip to cleanly remove PCI
device.

Change-Id: Ia60e8b69bda2b3bdd5990cb83f47c082d6667283
CRs-Fixed: 3308910

cnss2/pci.c

@@ -3234,8 +3234,12 @@ int cnss_pci_register_driver_hdlr(struct cnss_pci_data *pci_priv,
 
 int cnss_pci_unregister_driver_hdlr(struct cnss_pci_data *pci_priv)
 {
-	struct cnss_plat_data *plat_priv = pci_priv->plat_priv;
+	struct cnss_plat_data *plat_priv;
+
+	if (!pci_priv)
+		return -EINVAL;
 
+	plat_priv = pci_priv->plat_priv;
 	set_bit(CNSS_DRIVER_UNLOADING, &plat_priv->driver_state);
 	cnss_pci_dev_shutdown(pci_priv);
 	pci_priv->driver_ops = NULL;
@@ -5789,7 +5793,9 @@ static void cnss_pci_unregister_mhi(struct cnss_pci_data *pci_priv)
 
 	mhi_unregister_controller(mhi_ctrl);
 	kfree(mhi_ctrl->irq);
+	mhi_ctrl->irq = NULL;
 	mhi_free_controller(mhi_ctrl);
+	pci_priv->mhi_ctrl = NULL;
 }
 
 static void cnss_pci_config_regs(struct cnss_pci_data *pci_priv)
@@ -6166,6 +6172,7 @@ static void cnss_pci_remove(struct pci_dev *pci_dev)
 		cnss_bus_dev_to_plat_priv(&pci_dev->dev);
 
 	clear_bit(CNSS_PCI_PROBE_DONE, &plat_priv->driver_state);
+	cnss_pci_unregister_driver_hdlr(pci_priv);
 	cnss_pci_free_m3_mem(pci_priv);
 	cnss_pci_free_fw_mem(pci_priv);
 	cnss_pci_free_qdss_mem(pci_priv);