From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> commit 36af2d5c4433fb40ee2af912c4ac0a30991aecfc upstream. Commit 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") may create two "MODALIAS=" in one uevent file if specific conditions are met. This breaks systemd-udevd, which assumes each "key" in one uevent file to be unique. The internal implementation of systemd-udevd overwrites the first MODALIAS with the second one, so its kmod rule doesn't load the driver for the first MODALIAS. So if both the ACPI modalias and the OF modalias are present, use the latter to ensure that there will be only one MODALIAS. Link: https://github.com/systemd/systemd/pull/18163 Suggested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: 4.1+ <stable@xxxxxxxxxxxxxxx> # 4.1+ [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/device_sysfs.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -259,20 +259,12 @@ int __acpi_device_uevent_modalias(struct if (add_uevent_var(env, "MODALIAS=")) return -ENOMEM; - len = create_pnp_modalias(adev, &env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen); - if (len < 0) - return len; - - env->buflen += len; - if (!adev->data.of_compatible) - return 0; - - if (len > 0 && add_uevent_var(env, "MODALIAS=")) - return -ENOMEM; - - len = create_of_modalias(adev, &env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen); + if (adev->data.of_compatible) + len = create_of_modalias(adev, &env->buf[env->buflen - 1], + sizeof(env->buf) - env->buflen); + else + len = create_pnp_modalias(adev, &env->buf[env->buflen - 1], + sizeof(env->buf) - env->buflen); if (len < 0) return len;