From ec1cc298d28867c4eca9127cb24a5b18ea94265b Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 8 Apr 2020 19:38:02 +0200 Subject: [PATCH] gpu: host1x: Detach driver on unregister [ Upstream commit d9a0a05bf8c76e6dc79230669a8b5d685b168c30 ] Currently when a host1x device driver is unregistered, it is not detached from the host1x controller, which means that the device will stay around and when the driver is registered again, it may bind to the old, stale device rather than the new one that was created from scratch upon driver registration. This in turn can cause various weird crashes within the driver core because it is confronted with a device that was already deleted. Fix this by detaching the driver from the host1x controller when it is unregistered. This ensures that the deleted device also is no longer present in the device list that drivers will bind to. Reported-by: Sowjanya Komatineni Signed-off-by: Thierry Reding Tested-by: Sowjanya Komatineni Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/gpu/host1x/bus.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c index c27858ae0552..6ef89e8a515a 100644 --- a/drivers/gpu/host1x/bus.c +++ b/drivers/gpu/host1x/bus.c @@ -542,8 +542,17 @@ EXPORT_SYMBOL(host1x_driver_register_full); void host1x_driver_unregister(struct host1x_driver *driver) { + struct host1x *host1x; + driver_unregister(&driver->driver); + mutex_lock(&devices_lock); + + list_for_each_entry(host1x, &devices, list) + host1x_detach_driver(host1x, driver); + + mutex_unlock(&devices_lock); + mutex_lock(&drivers_lock); list_del_init(&driver->list); mutex_unlock(&drivers_lock);