From: Breno Leitao <leitao@debian.org>
To: Jakub Kicinski <kuba@kernel.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com,
pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org,
michael.chan@broadcom.com, pavan.chebbi@broadcom.com,
sdf@fomichev.me, aleksandr.loktionov@intel.com
Subject: Re: [PATCH net] Reapply "bnxt_en: bring back rtnl_lock() in the bnxt_open() path"
Date: Thu, 4 Jun 2026 01:17:07 -0700 [thread overview]
Message-ID: <aiE0Z74p1ey14I5A@gmail.com> (raw)
In-Reply-To: <20260603195845.2574426-1-kuba@kernel.org>
On Wed, Jun 03, 2026 at 12:58:45PM -0700, Jakub Kicinski wrote:
> This reverts commit 850d9248d2eac662f869c766a598c877690c74e5.
> This reapplies commit 325eb217e41f ("bnxt_en: bring back rtnl_lock()
> in the bnxt_open() path").
>
> Breno reports a lockdep warning in bnxt. During FW reset the driver
> may end up calling netif_set_real_num_tx_queues() (if queue count
> changes), so calls to bnxt_open() still require rtnl_lock.
>
> net/sched/sch_generic.c:1416 suspicious rcu_dereference_protected() usage!
>
> dev_qdisc_change_real_num_tx+0x54/0xe0
> netif_set_real_num_tx_queues+0x4ed/0xa80
> __bnxt_open_nic+0x9cb/0x3490
> bnxt_open+0x1cb/0x370
> bnxt_fw_reset_task+0x80d/0x1e80
> process_scheduled_works+0x9c1/0x13b0
>
> The reverted commit was just an optimization / experiment
> so let's go back to taking the lock.
>
> Reported-by: Breno Leitao <leitao@debian.org>
> Link: https://lore.kernel.org/ah726OtFX-Qw3U-R@gmail.com
> Fixes: 850d9248d2ea ("Revert "bnxt_en: bring back rtnl_lock() in the bnxt_open() path"")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
next prev parent reply other threads:[~2026-06-04 8:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-03 19:58 [PATCH net] Reapply "bnxt_en: bring back rtnl_lock() in the bnxt_open() path" Jakub Kicinski
2026-06-03 20:30 ` Stanislav Fomichev
2026-06-03 21:06 ` Michael Chan
2026-06-04 8:17 ` Breno Leitao [this message]
2026-06-04 16:20 ` patchwork-bot+netdevbpf
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