ACPI: sysfs: Prefer "compatible" modalias

stable inclusion
from stable-5.10.13
commit d6f80e01fade80c472671138114a87559d73335b
bugzilla: 47995

--------------------------------

commit 36af2d5c upstream.

Commit 8765c5ba ("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/18163Suggested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Fixes: 8765c5ba ("ACPI / scan: Rework modalias creation when "compatible" is present")
Signed-off-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
[ rjw: Subject and changelog edits ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/acpi/device_sysfs.c

@@ -251,20 +251,12 @@ int __acpi_device_uevent_modalias(struct acpi_device *adev,
 	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;
-
+	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;