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Subject[PATCH] driver core: unbind consumers before locking parent on device unbind
Date
On forced unbind the parent lock is taken, as the device might be a USB
device. The device to be unbound might have active consumers, which
must be unbound before calling device_release_driver(), otherwise this
function might deadlock when trying to take the parent lock during
consumer unbind.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
drivers/base/bus.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 6470eb8088f4..23df171a6a64 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -186,6 +186,9 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf,

dev = bus_find_device_by_name(bus, NULL, buf);
if (dev && dev->driver == drv) {
+ while (device_links_busy(dev)) {
+ device_links_unbind_consumers(dev);
+ }
if (dev->parent) /* Needed for USB */
device_lock(dev->parent);
device_release_driver(dev);
--
2.11.0
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