[PATCH 5.9 020/391] firmware: arm_scmi: Fix duplicate workqueue name

From: Greg Kroah-Hartman
Date: Tue Nov 03 2020 - 17:09:14 EST


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

[ Upstream commit b9ceca6be43233845be70792be9b5ab315d2e010 ]

When more than a single SCMI device are present in the system, the
creation of the notification workqueue with the WQ_SYSFS flag will lead
to the following sysfs duplicate node warning:

sysfs: cannot create duplicate filename '/devices/virtual/workqueue/scmi_notify'
CPU: 0 PID: 20 Comm: kworker/0:1 Not tainted 5.9.0-gdf4dd84a3f7d #29
Hardware name: Broadcom STB (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
Backtrace:
show_stack + 0x20/0x24
dump_stack + 0xbc/0xe0
sysfs_warn_dup + 0x70/0x80
sysfs_create_dir_ns + 0x15c/0x1a4
kobject_add_internal + 0x140/0x4d0
kobject_add + 0xc8/0x138
device_add + 0x1dc/0xc20
device_register + 0x24/0x28
workqueue_sysfs_register + 0xe4/0x1f0
alloc_workqueue + 0x448/0x6ac
scmi_notification_init + 0x78/0x1dc
scmi_probe + 0x268/0x4fc
platform_drv_probe + 0x70/0xc8
really_probe + 0x184/0x728
driver_probe_device + 0xa4/0x278
__device_attach_driver + 0xe8/0x148
bus_for_each_drv + 0x108/0x158
__device_attach + 0x190/0x234
device_initial_probe + 0x1c/0x20
bus_probe_device + 0xdc/0xec
deferred_probe_work_func + 0xd4/0x11c
process_one_work + 0x420/0x8f0
worker_thread + 0x4fc/0x91c
kthread + 0x21c/0x22c
ret_from_fork + 0x14/0x20
kobject_add_internal failed for scmi_notify with -EEXIST, don't try to
register things with the same name in the same directory.
arm-scmi brcm_scmi@1: SCMI Notifications - Initialization Failed.
arm-scmi brcm_scmi@1: SCMI Notifications NOT available.
arm-scmi brcm_scmi@1: SCMI Protocol v1.0 'brcm-scmi:' Firmware version 0x1

Fix this by using dev_name(handle->dev) which guarantees that the name is
unique and this also helps correlate which notification workqueue corresponds
to which SCMI device instance.

Link: https://lore.kernel.org/r/20201014021737.287340-1-f.fainelli@xxxxxxxxx
Fixes: bd31b249692e ("firmware: arm_scmi: Add notification dispatch and delivery")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
[sudeep.holla: trimmed backtrace to remove all unwanted hexcodes and timestamps]
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/firmware/arm_scmi/notify.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index 4d9f6de3a7fae..51c5a376fb472 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -1474,7 +1474,7 @@ int scmi_notification_init(struct scmi_handle *handle)
ni->gid = gid;
ni->handle = handle;

- ni->notify_wq = alloc_workqueue("scmi_notify",
+ ni->notify_wq = alloc_workqueue(dev_name(handle->dev),
WQ_UNBOUND | WQ_FREEZABLE | WQ_SYSFS,
0);
if (!ni->notify_wq)
--
2.27.0