serdev: Fix serdev_uevent failure on ACPI enumerated serdev-controllers

ACPI enumerated serdev-controllers do not have an ACPI companion, the ACPI
companion belongs to the serdev-device child of the serdev-controller, not
to the controller itself. This was causing serdev_uevent to always return
-ENODEV when called on a serdev-controller leading to errors like these:

kernel: serial serial0: uevent: failed to send synthetic uevent

being logged. This commit modifies serdev_uevent to directly return 0
when called on an ACPI enumerated serdev-controller fixing this.

Note: I do not think that setting a modalias on a devicetree enumerated
serdev-controller makes sense either. So perhaps the !dev->of_node part of
the check can be dropped too, but I'm not entirely sure that doing this
on devicetree too is correct.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 28133dbd2808fde58201d80f822249aeedcabdeb..5dc88f61f5063aede1e925eaae73dc6436c68598 100644 (file)
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -54,6 +54,11 @@ static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
        int rc;
 
        /* TODO: platform modalias */
+
+       /* ACPI enumerated controllers do not have a modalias */
+       if (!dev->of_node && dev->type == &serdev_ctrl_type)
+               return 0;
+
        rc = acpi_device_uevent_modalias(dev, env);
        if (rc != -ENODEV)
                return rc;