| Message ID | 20210119092327.310934-1-kai.heng.feng@canonical.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v2] ACPI / device_sysfs: Use OF_MODALIAS for "compatible" modalias | expand |
diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c index 96869f1538b9..17483c40deeb 100644 --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -260,7 +260,11 @@ int __acpi_device_uevent_modalias(struct acpi_device *adev, if (!adev->data.of_compatible) return 0; - if (len > 0 && add_uevent_var(env, "MODALIAS=")) + /* Two "MODALIAS=" breaks how systemd-udevd handles uevent file. + * As userspace may not be able to handle duplicated keys, add prefix + * "OF_" to avoid the key collision. + */ + if (len > 0 && add_uevent_var(env, "OF_MODALIAS=")) return -ENOMEM; len = create_of_modalias(adev, &env->buf[env->buflen - 1],
Commit 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") may create two "MODALIAS=" in uevent file if conditions are met. This breaks systemd-udevd, which assumes each "key" in uevent file is unique. The internal implementation of systemd-udevd overwrites the first MODALIAS with the second one, so its kmod rule doesn't load driver for the first MODALIAS. Right now it doesn't seem to have any user relies on the second MODALIAS, so change it to OF_MODALIAS to workaround the issue. Reference: https://github.com/systemd/systemd/pull/18163 Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- v2: Add a comment to document why it's changed. drivers/acpi/device_sysfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)