[PATCH] brcmfmac: pcie: Fix crashes due to early IRQs

[Hector Martin <marcan@xxxxxxxxx>]

The driver was enabling IRQs before the message processing was
initialized. This could cause IRQs to come in too early and crash the
driver. Instead, move the IRQ enable and hostready to a bus preinit
function, at which point everything is properly initialized.

Fixes: 9e37f045d5e7 ("brcmfmac: Adding PCIe bus layer support.")
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220131160713.245637-7-marcan@xxxxxxxxx

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
index 3f3ca7612bcd..55f0111283c9 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -1315,6 +1315,18 @@ static void brcmf_pcie_down(struct device *dev)
 {
 }
 
+static int brcmf_pcie_preinit(struct device *dev)
+{
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_pciedev *buspub = bus_if->bus_priv.pcie;
+
+	brcmf_dbg(PCIE, "Enter\n");
+
+	brcmf_pcie_intr_enable(buspub->devinfo);
+	brcmf_pcie_hostready(buspub->devinfo);
+
+	return 0;
+}
 
 static int brcmf_pcie_tx(struct device *dev, struct sk_buff *skb)
 {
@@ -1423,6 +1435,7 @@ static int brcmf_pcie_reset(struct device *dev)
 }
 
 static const struct brcmf_bus_ops brcmf_pcie_bus_ops = {
+	.preinit = brcmf_pcie_preinit,
 	.txdata = brcmf_pcie_tx,
 	.stop = brcmf_pcie_down,
 	.txctl = brcmf_pcie_tx_ctlpkt,
@@ -1795,9 +1808,6 @@ static void brcmf_pcie_setup(struct device *dev, int ret,
 
 	init_waitqueue_head(&devinfo->mbdata_resp_wait);
 
-	brcmf_pcie_intr_enable(devinfo);
-	brcmf_pcie_hostready(devinfo);
-
 	ret = brcmf_attach(&devinfo->pdev->dev);
 	if (ret)
 		goto fail;