Running a kernel with the fusb302 driver and lockdep enabled
leads to an unpleasant warning:
[ 4.617477] INFO: trying to register non-static key.
[ 4.617930] the code is fine but needs lockdep annotation.
[ 4.618418] turning off the locking correctness validator.
[ 4.618913] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-00007-g3542533f3fc9 #13
[ 4.619620] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[ 4.620454] Call trace:
[ 4.620693] dump_backtrace+0x0/0x138
[ 4.621028] show_stack+0x24/0x30
[ 4.621336] dump_stack+0xbc/0x104
[ 4.621649] register_lock_class+0x594/0x598
[ 4.622036] __lock_acquire+0x80/0x11b8
[ 4.622384] lock_acquire+0xdc/0x260
[ 4.622711] __mutex_lock+0x90/0x8a0
[ 4.623037] mutex_lock_nested+0x3c/0x50
[ 4.623394] _fusb302_log+0x88/0x1f0
[ 4.623721] fusb302_log+0x7c/0xa0
[ 4.624033] tcpm_init+0x5c/0x190
[ 4.624336] tcpm_init+0x3c/0x130
[ 4.624640] tcpm_register_port+0x574/0x878
[ 4.625019] fusb302_probe+0x2c8/0x590
Despite what the message says, the code isn't fine, as it tries to
make use of the fusb302_log facility pretty early. This requires the
logbuffer_lock mutex to be initialised, but that only happens much
later. Boo.
Hoist the fusb302_debugfs_init call before tcpm_register_port so that
we can enjoy a working mutex.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
drivers/usb/typec/tcpm/fusb302.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c
index e9344997329c..7e3f8901daf6 100644
--- a/drivers/usb/typec/tcpm/fusb302.c
+++ b/drivers/usb/typec/tcpm/fusb302.c
@@ -1790,6 +1790,7 @@ static int fusb302_probe(struct i2c_client *client,
goto destroy_workqueue;
}
+ fusb302_debugfs_init(chip);
chip->tcpm_port = tcpm_register_port(&client->dev, &chip->tcpc_dev);
if (IS_ERR(chip->tcpm_port)) {
ret = PTR_ERR(chip->tcpm_port);
@@ -1807,7 +1808,6 @@ static int fusb302_probe(struct i2c_client *client,
goto tcpm_unregister_port;
}
enable_irq_wake(chip->gpio_int_n_irq);
- fusb302_debugfs_init(chip);
i2c_set_clientdata(client, chip);
return ret;
--
2.20.1
