Re: [PATCH v5.1-rc] iwlwifi: make locking in iwl_mvm_tx_mpdu() BH-safe
- Date: Mon, 15 Apr 2019 13:10:45 +0200
- From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
- Subject: Re: [PATCH v5.1-rc] iwlwifi: make locking in iwl_mvm_tx_mpdu() BH-safe
On Mon, 2019-04-15 at 13:03 +0200, Jiri Kosina wrote:
(FWIW, would be good to cc linux-wireless, but no need for linux-kernel
I guess :-) )
> iwl_mvm_sta->lock can be taken from BH, and therefore BH must be disabled if
> taking it from other contexts.
> This fixes the lockdep warning below.
I don't think this is the right fix.
The only problem is this path:
> SOFTIRQ-ON-W at:
> iwl_mvm_tx_mpdu+0xae/0x5f0 [iwlmvm]
> iwl_mvm_tx_skb+0x200/0x470 [iwlmvm]
> iwl_mvm_mac_itxq_xmit+0xd5/0x1f0 [iwlmvm]
> iwl_mvm_add_new_dqa_stream_wk+0x34c/0x910 [iwlmvm]
which I believe we just made use local_bh_disable() since there are
other reasons as well for that, IIRC.
Yes, here's the fix:
It's on the way upstream.
Thanks for the patch/report though!