[PATCH 5.5 251/399] driver core: Print device when resources present in really_probe()

Greg Kroah-Hartman
2020-02-21T08:43:01Z

From: Geert Uytterhoeven <geert+renesas@glider.be>

[ Upstream commit 7c35e699c88bd60734277b26962783c60e04b494 ]

If a device already has devres items attached before probing, a warning
backtrace is printed. However, this backtrace does not reveal the
offending device, leaving the user uninformed. Furthermore, using
WARN_ON() causes systems with panic-on-warn to reboot.

Fix this by replacing the WARN_ON() by a dev_crit() message.
Abort probing the device, to prevent doing more damage to the device's
resources.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191206132219.28908-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/dd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index d811e60610d33..b25bcab2a26bd 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -516,7 +516,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
atomic_inc(&probe_count);
pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
drv->bus->name, __func__, drv->name, dev_name(dev));
- WARN_ON(!list_empty(&dev->devres_head));
+ if (!list_empty(&dev->devres_head)) {
+ dev_crit(dev, "Resources present before probing\n");
+ return -EBUSY;
+ }

re_probe:
dev->driver = drv;
--
2.20.1