On Thu, Aug 19, 2021 at 11:19:34PM +0300, Sakari Ailus wrote:

Return -EPROBE_DEFER if probing the device fails because of the I²C
transaction (-EIO only). This generally happens when the power on sequence
of the device has not been fully performed yet due to later probing of
other drivers.

...

+	if (ret == -EIO && is_acpi_device_node(dev_fwnode(&client->dev))) {

has_acpi_companion() is better to have here, no?

+		/*
+		 * If we get -EIO here and it's an ACPI device, there's a fair
+		 * likelihood it's because the drivers required to power this
+		 * device on have not probed yet. Thus return -EPROBE_DEFER.
+		 */
+		return -EPROBE_DEFER;
+	}

-- 
With Best Regards,
Andy Shevchenko