From 7b1f781f2d2460693f43d5f764198df558e3494b Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Tue, 15 Feb 2022 13:32:26 -0800 Subject: [PATCH] Input: psmouse - set up dependency between PS/2 and SMBus companions When we switch from emulated PS/2 to native (RMI4 or Elan) protocols, we create SMBus companion devices that are attached to I2C/SMBus controllers. However, when suspending and resuming, we also need to make sure that we take into account the PS/2 device they are associated with, so that PS/2 device is suspended after the companion and resumed before it, otherwise companions will not work properly. Before I2C devices were marked for asynchronous suspend/resume, this ordering happened naturally, but now we need to enforce it by establishing device links, with PS/2 devices being suppliers and SMBus companions being consumers. Fixes: 172d931910e1 ("i2c: enable async suspend/resume on i2c client devices") Reported-and-tested-by: Hugh Dickins Tested-by: Jarkko Nikula Link: https://lore.kernel.org/r/89456fcd-a113-4c82-4b10-a9bcaefac68f@google.com Link: https://lore.kernel.org/r/YgwQN8ynO88CPMju@google.com Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/psmouse-smbus.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/input/mouse/psmouse-smbus.c b/drivers/input/mouse/psmouse-smbus.c index a472489ccbad..164f6c757f6b 100644 --- a/drivers/input/mouse/psmouse-smbus.c +++ b/drivers/input/mouse/psmouse-smbus.c @@ -75,6 +75,8 @@ static void psmouse_smbus_detach_i2c_client(struct i2c_client *client) "Marking SMBus companion %s as gone\n", dev_name(&smbdev->client->dev)); smbdev->dead = true; + device_link_remove(&smbdev->client->dev, + &smbdev->psmouse->ps2dev.serio->dev); serio_rescan(smbdev->psmouse->ps2dev.serio); } else { list_del(&smbdev->node); @@ -174,6 +176,8 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse) kfree(smbdev); } else { smbdev->dead = true; + device_link_remove(&smbdev->client->dev, + &psmouse->ps2dev.serio->dev); psmouse_dbg(smbdev->psmouse, "posting removal request for SMBus companion %s\n", dev_name(&smbdev->client->dev)); @@ -270,6 +274,12 @@ int psmouse_smbus_init(struct psmouse *psmouse, if (smbdev->client) { /* We have our companion device */ + if (!device_link_add(&smbdev->client->dev, + &psmouse->ps2dev.serio->dev, + DL_FLAG_STATELESS)) + psmouse_warn(psmouse, + "failed to set up link with iSMBus companion %s\n", + dev_name(&smbdev->client->dev)); return 0; }