On 11/4/20 5:29 AM, Srinivas Kandagatla wrote:

running kernel with CONFIG_DEBUG_LOCKS_ALLOC enabled will below warning:

BUG: key ffff502e09807098 has not been registered! DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 5 PID: 129 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0xe8/0x250 Modules linked in: CPU: 5 PID: 129 Comm: kworker/5:1 Tainted: G W 5.10.0-rc1-00277-ged49f224ca3f-dirty #1210 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Workqueue: events deferred_probe_work_func pstate: 80c00005 (Nzcv daif +PAN +UAO -TCO BTYPE=--) pc : lockdep_init_map_waits+0xe8/0x250 lr : lockdep_init_map_waits+0xe8/0x250 [ Trimmed ]

Call trace: lockdep_init_map_waits+0xe8/0x250 __kernfs_create_file+0x78/0x180 sysfs_add_file_mode_ns+0x94/0x1c8 internal_create_group+0x110/0x3e0 sysfs_create_group+0x18/0x28 devm_device_add_group+0x4c/0xb0 add_all_attributes+0x438/0x490 sdw_slave_sysfs_dpn_init+0x128/0x138 sdw_slave_sysfs_init+0x80/0xa0 sdw_drv_probe+0x94/0x170 really_probe+0x118/0x3e0 driver_probe_device+0x5c/0xc0

[ Trimmed ]

CPU: 5 PID: 129 Comm: kworker/5:1 Tainted: G W 5.10.0-rc1-00277-ged49f224ca3f-dirty #1210 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Workqueue: events deferred_probe_work_func Call trace: dump_backtrace+0x0/0x1c0 show_stack+0x18/0x68 dump_stack+0xd8/0x134 __warn+0xa0/0x158 report_bug+0xc8/0x178 bug_handler+0x20/0x78 brk_handler+0x70/0xc8

[ Trimmed ]

Fix this by initializing dynamically allocated sysfs attribute to keep lockdep happy!

Fixes: bcac59029955 ("soundwire: add Slave sysfs support") Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org

I added the exact same fix last Friday but you beat me to it.

Acked-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

My commit message was a bit more self-explanatory though, maybe you could add the explanation at the end and possibly trim the logs?

" when CONFIG_DEBUG_LOCK_ALLOC is enabled, a warning is thrown, e.g.

kernel: [ 4.078863] BUG: key ffff8a9203c92dc0 has not been registered! kernel: [ 4.078865] ------------[ cut here ]------------ kernel: [ 4.078866] DEBUG_LOCKS_WARN_ON(1) kernel: [ 4.078871] WARNING: CPU: 0 PID: 280 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x177/0x200 kernel: [ 4.078902] Call Trace: kernel: [ 4.078906] __kernfs_create_file+0x76/0x100 kernel: [ 4.078908] sysfs_add_file_mode_ns+0x9f/0x190 kernel: [ 4.078909] internal_create_group+0x112/0x380 kernel: [ 4.078912] devm_device_add_group+0x41/0x80 kernel: [ 4.078915] add_all_attributes+0x4bf/0x4e0 [soundwire_bus] kernel: [ 4.078918] sdw_slave_sysfs_dpn_init+0x68/0xe0 [soundwire_bus] kernel: [ 4.078920] sdw_slave_sysfs_init+0x6b/0x80 [soundwire_bus]

For DPn ports, the attributes are allocated dynamically and it's required to use the macro sysfs_attr_init(), whose behavior is precisely dependent on CONFIG_DEBUG_LOCK_ALLOC. See details in linux/sysfs.h. "

Thanks Srinivas!

---

drivers/soundwire/sysfs_slave_dpn.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/soundwire/sysfs_slave_dpn.c b/drivers/soundwire/sysfs_slave_dpn.c index 05a721ea9830..c4b6543c09fd 100644 --- a/drivers/soundwire/sysfs_slave_dpn.c +++ b/drivers/soundwire/sysfs_slave_dpn.c @@ -37,6 +37,7 @@ static int field##_attribute_alloc(struct device *dev, \ return -ENOMEM; \ dpn_attr->N = N; \ dpn_attr->dir = dir; \

• sysfs_attr_init(&dpn_attr->dev_attr.attr); \ dpn_attr->format_string = format_string; \ dpn_attr->dev_attr.attr.name = __stringify(field); \ dpn_attr->dev_attr.attr.mode = 0444; \