[RFC] thermal/core: Disable uevent messages for cooling devices

From: Roman Stratiienko
Date: Sun Jul 10 2022 - 12:40:46 EST

During suspend, the big CPU cluster is turned off first while a little
is still running. This forcibly unregisters the cooling device which
sends a "REMOVE" uevent to all subscribers [1].

In case userspace netlink subscriber has set the EPOLLWAKEUP flag, a
wakeup event is triggered that causes suspend to be aborted.

Without this change, suspend doesn't work on PinePhone PRO with AOSP

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c238a8b599f1ae25eaeb08ad0e9e13e2b9eb023
Signed-off-by: Roman Stratiienko <r.stratiienko@xxxxxxxxx>
drivers/thermal/thermal_core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index cdc0552e8c42e..e6b21f2792a85 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -925,6 +925,7 @@ __thermal_cooling_device_register(struct device_node *np,
cdev->device.class = &thermal_class;
cdev->devdata = devdata;
+ dev_set_uevent_suppress(&cdev->device, true);
ret = device_register(&cdev->device);
if (ret)
goto out_kfree_type;