On Mon, 27 Dec 2021 10:45:16 +0100This was the reason why second counter instance initialization failed for me when testing the patch 17. I fixed it locally by changing the line a few rows above the MKDEV():
Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
+ if (err < 0)
+ goto err_chrdev_add;
+
+ device_initialize(dev);
+ /* Configure device structure for Counter */
+ dev->type = &counter_device_type;
+ dev->bus = &counter_bus_type;
+ dev->devt = MKDEV(MAJOR(counter_devt), id);
As 0-day pointed out id not initialized.