[Bug 2171046] Re: Firmware-less serdev device returns ENODEV for modalias, breaking sysfs enumeration

** Tags added: kernel-daily-bug -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2171046 Title: Firmware-less serdev device returns ENODEV for modalias, breaking sysfs enumeration Status in linux package in Ubuntu: New Status in linux source package in Resolute: New Bug description: The Dell UART backlight driver creates a  serial0-0  serdev device without ACPI or Device Tree firmware metadata. When userspace reads its  modalias  sysfs file, serdev tries to generate an alias from ACPI and OF data; both lookups return  -ENODEV , which serdev incorrectly propagates as a read failure. The modalias should instead be readable with empty content, because this manually created device has no firmware alias. Returning  -ENODEV  makes sysfs enumeration fail and causes Checkbox  dkms_info_attachment  to abort. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2171046/+subscriptions