Patch "serdev: Fix serdev_uevent failure on ACPI enumerated serdev-controllers" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    serdev: Fix serdev_uevent failure on ACPI enumerated serdev-controllers

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serdev-fix-serdev_uevent-failure-on-acpi-enumerated-serdev-controllers.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Apr  9 10:16:32 CEST 2018
From: Hans de Goede <hdegoede@redhat.com>
Date: Mon, 25 Dec 2017 21:50:45 +0100
Subject: serdev: Fix serdev_uevent failure on ACPI enumerated serdev-controllers

From: Hans de Goede <hdegoede@redhat.com>


[ Upstream commit 7d09995dcb0577b4a56aad7f2bb56f28604e8f1a ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serdev/core.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -54,6 +54,11 @@ static int serdev_uevent(struct device *
 	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;


Patches currently in stable-queue which might be from hdegoede@redhat.com are

queue-4.15/serdev-fix-serdev_uevent-failure-on-acpi-enumerated-serdev-controllers.patch
queue-4.15/acpi-video-default-lcd_only-to-true-on-win8-ready-and-newer-machines.patch
queue-4.15/bluetooth-hci_bcm-mandate-presence-of-shutdown-and-device-wake-gpio.patch
queue-4.15/input-goodix-disable-irqs-while-suspended.patch
queue-4.15/asoc-intel-cht_bsw_rt5645-analog-mic-support.patch
queue-4.15/power-supply-axp288_charger-properly-stop-work-on-probe-error-remove.patch
queue-4.15/pinctrl-baytrail-enable-glitch-filter-for-gpios-used-as-interrupts.patch