RE: [PATCH rtw-next] Revert "wifi: rtw88: add WQ_UNBOUND to alloc_workqueue users"

[Ping-Ke Shih <pkshih@realtek.com>]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
> This reverts commit 9c194fe4625db18f93d5abcfb7f7997557a0b29d.
> 
> This commit breaks all USB wifi adapters supported by rtw88:
> 
> usb 1-2: new high-speed USB device number 6 using xhci_hcd
> usb 1-2: New USB device found, idVendor=2357, idProduct=0138, bcdDevice= 2.10
> usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 1-2: Product: 802.11ac NIC
> usb 1-2: Manufacturer: Realtek
> usb 1-2: SerialNumber: 123456
> ------------[ cut here ]------------
> WARNING: CPU: 3 PID: 152 at kernel/workqueue.c:5667 alloc_workqueue_noprof+0x676/0x770
> 
> [...]
> 
> Call Trace:
>  <TASK>
>  ? rtw_usb_probe+0x30e/0xa5c [rtw88_usb 4af3cb64eedafeecbfb08f80c1e9e2893e2ee7a6]
>  rtw_usb_probe+0x3eb/0xa5c [rtw88_usb 4af3cb64eedafeecbfb08f80c1e9e2893e2ee7a6]
>  usb_probe_interface+0xdd/0x2c0
>  really_probe+0xdb/0x340
>  ? pm_runtime_barrier+0x55/0x90
>  ? __pfx___device_attach_driver+0x10/0x10
>  __driver_probe_device+0x78/0x140
>  driver_probe_device+0x1f/0xa0
>  __device_attach_driver+0x89/0x110
>  bus_for_each_drv+0x8f/0xe0
>  __device_attach+0xb0/0x1c0
>  bus_probe_device+0x90/0xa0
>  device_add+0x663/0x880
>  usb_set_configuration+0x5a5/0x870
>  usb_generic_driver_probe+0x4a/0x70
>  usb_probe_device+0x3d/0x140
>  ? driver_sysfs_add+0x59/0xd0
>  really_probe+0xdb/0x340
>  ? pm_runtime_barrier+0x55/0x90
>  ? __pfx___device_attach_driver+0x10/0x10
>  __driver_probe_device+0x78/0x140
>  driver_probe_device+0x1f/0xa0
>  __device_attach_driver+0x89/0x110
>  bus_for_each_drv+0x8f/0xe0
>  __device_attach+0xb0/0x1c0
>  bus_probe_device+0x90/0xa0
>  device_add+0x663/0x880
>  usb_new_device.cold+0x141/0x3b5
>  hub_event+0x1132/0x1900
>  ? page_counter_uncharge+0x4a/0x90
>  process_one_work+0x190/0x350
>  worker_thread+0x2d7/0x410
>  ? __pfx_worker_thread+0x10/0x10
>  kthread+0xf9/0x240
>  ? __pfx_kthread+0x10/0x10
>  ? __pfx_kthread+0x10/0x10
>  ret_from_fork+0x1c1/0x1f0
>  ? __pfx_kthread+0x10/0x10
>  ret_from_fork_asm+0x1a/0x30
>  </TASK>
> ---[ end trace 0000000000000000 ]---
> rtw88_8822bu 1-2:1.0: failed to create RX work queue
> rtw88_8822bu 1-2:1.0: failed to init USB RX
> rtw88_8822bu 1-2:1.0: Firmware version 27.2.0, H2C version 13
> rtw88_8822bu 1-2:1.0: probe with driver rtw88_8822bu failed with error -12
> 
> WQ_UNBOUND is not compatible with WQ_BH. Comment in enum wq_flags in
> workqueue.h says:
> 
>         /* BH wq only allows the following flags */
>         __WQ_BH_ALLOWS          = WQ_BH | WQ_HIGHPRI | WQ_PERCPU,

Thanks for the info. I'll take this patch to rtw tree in -rc cycle.

> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
> Fortunately this commit is not in any released kernel yet.
> ---
>  drivers/net/wireless/realtek/rtw88/usb.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
> index 22b9cbf2268a..bf6bedf7cb5f 100644
> --- a/drivers/net/wireless/realtek/rtw88/usb.c
> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
> @@ -972,8 +972,7 @@ static int rtw_usb_init_rx(struct rtw_dev *rtwdev)
>         struct sk_buff *rx_skb;
>         int i;
> 
> -       rtwusb->rxwq = alloc_workqueue("rtw88_usb: rx wq", WQ_BH | WQ_UNBOUND,
> -                                      0);

Hi Marco,

Will you send a patch to point out WQ_PERCPU explicitly?

> +       rtwusb->rxwq = alloc_workqueue("rtw88_usb: rx wq", WQ_BH, 0);
>         if (!rtwusb->rxwq) {
>                 rtw_err(rtwdev, "failed to create RX work queue\n");
>                 return -ENOMEM;
> --
> 2.51.1