[PATCH net] bnxt_en: Fix lockdep warning during rmmod

[PATCH net] bnxt_en: Fix lockdep warning during rmmod

[Michael Chan]

The commit under the Fixes tag added a netdev_assert_locked() in
bnxt_free_ntp_fltrs().  The lock should be held during normal run-time
but the assert will be triggered (see below) during bnxt_remove_one()
which should not need the lock.  The netdev is already unregistered by
then.  Fix it by only calling netdev_assert_locked() if the netdev is
registered.

WARNING: CPU: 5 PID: 2241 at ./include/net/netdev_lock.h:17 bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en]
Modules linked in: rpcrdma rdma_cm iw_cm ib_cm configfs ib_core bnxt_en(-) bridge stp llc x86_pkg_temp_thermal xfs tg3 [last unloaded: bnxt_re]
CPU: 5 UID: 0 PID: 2241 Comm: rmmod Tainted: G S      W           6.16.0 #2 PREEMPT(voluntary)
Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017
RIP: 0010:bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en]
Code: 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 47 60 be ff ff ff ff 48 8d b8 28 0c 00 00 e8 d0 cf 41 c3 85 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffa92082387da0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9e5b593d8000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff83dc9a70 RDI: ffffffff83e1a1cf
RBP: ffff9e5b593d8c80 R08: 0000000000000000 R09: ffffffff8373a2b3
R10: 000000008100009f R11: 0000000000000001 R12: 0000000000000001
R13: ffffffffc01c4478 R14: dead000000000122 R15: dead000000000100
FS:  00007f3a8a52c740(0000) GS:ffff9e631ad1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bb289419c8 CR3: 000000011274e001 CR4: 00000000003706f0
Call Trace:
 <TASK>
 bnxt_remove_one+0x57/0x180 [bnxt_en]
 pci_device_remove+0x39/0xc0
 device_release_driver_internal+0xa5/0x130
 driver_detach+0x42/0x90
 bus_remove_driver+0x61/0xc0
 pci_unregister_driver+0x38/0x90
 bnxt_exit+0xc/0x7d0 [bnxt_en]

Fixes: 004b5008016a ("eth: bnxt: remove most dependencies on RTNL")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 2800a90fba1f..a208c2a73cd6 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -5332,7 +5332,8 @@ static void bnxt_free_ntp_fltrs(struct bnxt *bp, bool all)
 {
 	int i;
 
-	netdev_assert_locked(bp->dev);
+	if (bp->dev->reg_state == NETREG_REGISTERED)
+		netdev_assert_locked(bp->dev);
 
 	/* Under netdev instance lock and all our NAPIs have been disabled.
 	 * It's safe to delete the hash table.
-- 
2.30.1

Re: [PATCH net] bnxt_en: Fix lockdep warning during rmmod

[Jakub Kicinski]

On Fri, 15 Aug 2025 10:08:23 -0700 Michael Chan wrote:
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index 2800a90fba1f..a208c2a73cd6 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -5332,7 +5332,8 @@ static void bnxt_free_ntp_fltrs(struct bnxt *bp, bool all)
>  {
>  	int i;
>  
> -	netdev_assert_locked(bp->dev);
> +	if (bp->dev->reg_state == NETREG_REGISTERED)
> +		netdev_assert_locked(bp->dev);
>  
>  	/* Under netdev instance lock and all our NAPIs have been disabled.
>  	 * It's safe to delete the hash table.

netdev_assert_locked_or_invisible()
-- 
pw-bot: cr