Brian Norris <briannorris@xxxxxxxxxxxx> writes:
> This reverts commit 5188d5453bc9380ccd4ae1086138dd485d13aef2, because it
> introduced lock recursion:
>
> BUG: spinlock recursion on CPU#2, kworker/u13:1/395
> lock: 0xffffffc0e28a47f0, .magic: dead4ead, .owner: kworker/u13:1/395, .owner_cpu: 2
> CPU: 2 PID: 395 Comm: kworker/u13:1 Not tainted 4.20.0-rc4+ #2
> Hardware name: Google Kevin (DT)
> Workqueue: MWIFIEX_RX_WORK_QUEUE mwifiex_rx_work_queue [mwifiex]
> Call trace:
> dump_backtrace+0x0/0x140
> show_stack+0x20/0x28
> dump_stack+0x84/0xa4
> spin_bug+0x98/0xa4
> do_raw_spin_lock+0x5c/0xdc
> _raw_spin_lock_irqsave+0x38/0x48
> mwifiex_flush_data+0x2c/0xa4 [mwifiex]
> call_timer_fn+0xcc/0x1c4
> run_timer_softirq+0x264/0x4f0
> __do_softirq+0x1a8/0x35c
> do_softirq+0x54/0x64
> netif_rx_ni+0xe8/0x120
> mwifiex_recv_packet+0xfc/0x10c [mwifiex]
> mwifiex_process_rx_packet+0x1d4/0x238 [mwifiex]
> mwifiex_11n_dispatch_pkt+0x190/0x1ac [mwifiex]
> mwifiex_11n_rx_reorder_pkt+0x28c/0x354 [mwifiex]
> mwifiex_process_sta_rx_packet+0x204/0x26c [mwifiex]
> mwifiex_handle_rx_packet+0x15c/0x16c [mwifiex]
> mwifiex_rx_work_queue+0x104/0x134 [mwifiex]
> worker_thread+0x4cc/0x72c
> kthread+0x134/0x13c
> ret_from_fork+0x10/0x18
>
> This was clearly not tested well at all. I simply performed 'wget' in a
> loop and it fell over within a few seconds.
>
> Fixes: 5188d5453bc9 ("mwifiex: restructure rx_reorder_tbl_lock usage")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Cc: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> ---
> This is a 4.19 regression, but IMO the revert should be merged ASAP.
Ok, I'll queue this for 4.20.
--
Kalle Valo
