Bluetooth: hci_bcm: Handle deferred probing for the clock supply

[ Upstream commit 28ac03b9ac3f784c2f048a910c8d0a7a87483b66 ]

On some systems that actually have the bluetooth controller wired up
with an extra clock signal, it's possible the bluetooth controller
probes before the clock provider. clk_get would return a defer probe
error, which was not handled by this driver.

Handle this properly, so that these systems can work reliably.
Tested-by: NOndrej Jirman <megous@megous.com>
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/bluetooth/hci_bcm.c

@@ -907,6 +907,10 @@ static int bcm_get_resources(struct bcm_device *dev)
 
 	dev->clk = devm_clk_get(dev->dev, NULL);
 
+	/* Handle deferred probing */
+	if (dev->clk == ERR_PTR(-EPROBE_DEFER))
+		return PTR_ERR(dev->clk);
+
 	dev->device_wakeup = devm_gpiod_get_optional(dev->dev, "device-wakeup",
 						     GPIOD_OUT_LOW);
 	if (IS_ERR(dev->device_wakeup))