* [PATCH net v2 1/2] net: macb: Move devm_{free,request}_irq() out of spin lock area
2026-03-18 6:36 [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used Kevin Hao
@ 2026-03-18 6:36 ` Kevin Hao
2026-03-18 6:36 ` [PATCH net v2 2/2] net: macb: Protect access to net_device::ip_ptr with RCU lock Kevin Hao
2026-03-21 1:30 ` [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used patchwork-bot+netdevbpf
2 siblings, 0 replies; 5+ messages in thread
From: Kevin Hao @ 2026-03-18 6:36 UTC (permalink / raw)
To: netdev
Cc: Nicolas Ferre, Claudiu Beznea, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Vineeth Karumanchi,
Harini Katakam, Théo Lebrun, Kevin Hao, stable
The devm_free_irq() and devm_request_irq() functions should not be
executed in an atomic context.
During device suspend, all userspace processes and most kernel threads
are frozen. Additionally, we flush all tx/rx status, disable all macb
interrupts, and halt rx operations. Therefore, it is safe to split the
region protected by bp->lock into two independent sections, allowing
devm_free_irq() and devm_request_irq() to run in a non-atomic context.
This modification resolves the following lockdep warning:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 501, name: rtcwake
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 0
7 locks held by rtcwake/501:
#0: ffff0008038c3408 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0xf8/0x368
#1: ffff0008049a5e88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0xbc/0x1c8
#2: ffff00080098d588 (kn->active#70){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xcc/0x1c8
#3: ffff800081c84888 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x1ec/0x290
#4: ffff0008009ba0f8 (&dev->mutex){....}-{4:4}, at: device_suspend+0x118/0x4f0
#5: ffff800081d00458 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48
#6: ffff0008031fb9e0 (&bp->lock){-.-.}-{3:3}, at: macb_suspend+0x144/0x558
irq event stamp: 8682
hardirqs last enabled at (8681): [<ffff8000813c7d7c>] _raw_spin_unlock_irqrestore+0x44/0x88
hardirqs last disabled at (8682): [<ffff8000813c7b58>] _raw_spin_lock_irqsave+0x38/0x98
softirqs last enabled at (7322): [<ffff8000800f1b4c>] handle_softirqs+0x52c/0x588
softirqs last disabled at (7317): [<ffff800080010310>] __do_softirq+0x20/0x2c
CPU: 1 UID: 0 PID: 501 Comm: rtcwake Not tainted 7.0.0-rc3-next-20260310-yocto-standard+ #125 PREEMPT
Hardware name: ZynqMP ZCU102 Rev1.1 (DT)
Call trace:
show_stack+0x24/0x38 (C)
__dump_stack+0x28/0x38
dump_stack_lvl+0x64/0x88
dump_stack+0x18/0x24
__might_resched+0x200/0x218
__might_sleep+0x38/0x98
__mutex_lock_common+0x7c/0x1378
mutex_lock_nested+0x38/0x50
free_irq+0x68/0x2b0
devm_irq_release+0x24/0x38
devres_release+0x40/0x80
devm_free_irq+0x48/0x88
macb_suspend+0x298/0x558
device_suspend+0x218/0x4f0
dpm_suspend+0x244/0x3a0
dpm_suspend_start+0x50/0x78
suspend_devices_and_enter+0xec/0x560
pm_suspend+0x194/0x290
state_store+0x110/0x158
kobj_attr_store+0x1c/0x30
sysfs_kf_write+0xa8/0xd0
kernfs_fop_write_iter+0x11c/0x1c8
vfs_write+0x248/0x368
ksys_write+0x7c/0xf8
__arm64_sys_write+0x28/0x40
invoke_syscall+0x4c/0xe8
el0_svc_common+0x98/0xf0
do_el0_svc+0x28/0x40
el0_svc+0x54/0x1e0
el0t_64_sync_handler+0x84/0x130
el0t_64_sync+0x198/0x1a0
Fixes: 558e35ccfe95 ("net: macb: WoL support for GEM type of Ethernet controller")
Cc: stable@vger.kernel.org
Reviewed-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
drivers/net/ethernet/cadence/macb_main.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 36ab3b7e1feabd295be35152f0b464bba6fcbe18..2d4304331e297accd91ab48813a9bd4722ce72dc 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -5968,6 +5968,7 @@ static int __maybe_unused macb_suspend(struct device *dev)
/* write IP address into register */
tmp |= MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local));
}
+ spin_unlock_irqrestore(&bp->lock, flags);
/* Change interrupt handler and
* Enable WoL IRQ on queue 0
@@ -5980,11 +5981,12 @@ static int __maybe_unused macb_suspend(struct device *dev)
dev_err(dev,
"Unable to request IRQ %d (error %d)\n",
bp->queues[0].irq, err);
- spin_unlock_irqrestore(&bp->lock, flags);
return err;
}
+ spin_lock_irqsave(&bp->lock, flags);
queue_writel(bp->queues, IER, GEM_BIT(WOL));
gem_writel(bp, WOL, tmp);
+ spin_unlock_irqrestore(&bp->lock, flags);
} else {
err = devm_request_irq(dev, bp->queues[0].irq, macb_wol_interrupt,
IRQF_SHARED, netdev->name, bp->queues);
@@ -5992,13 +5994,13 @@ static int __maybe_unused macb_suspend(struct device *dev)
dev_err(dev,
"Unable to request IRQ %d (error %d)\n",
bp->queues[0].irq, err);
- spin_unlock_irqrestore(&bp->lock, flags);
return err;
}
+ spin_lock_irqsave(&bp->lock, flags);
queue_writel(bp->queues, IER, MACB_BIT(WOL));
macb_writel(bp, WOL, tmp);
+ spin_unlock_irqrestore(&bp->lock, flags);
}
- spin_unlock_irqrestore(&bp->lock, flags);
enable_irq_wake(bp->queues[0].irq);
}
@@ -6065,6 +6067,8 @@ static int __maybe_unused macb_resume(struct device *dev)
queue_readl(bp->queues, ISR);
if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
queue_writel(bp->queues, ISR, -1);
+ spin_unlock_irqrestore(&bp->lock, flags);
+
/* Replace interrupt handler on queue 0 */
devm_free_irq(dev, bp->queues[0].irq, bp->queues);
err = devm_request_irq(dev, bp->queues[0].irq, macb_interrupt,
@@ -6073,10 +6077,8 @@ static int __maybe_unused macb_resume(struct device *dev)
dev_err(dev,
"Unable to request IRQ %d (error %d)\n",
bp->queues[0].irq, err);
- spin_unlock_irqrestore(&bp->lock, flags);
return err;
}
- spin_unlock_irqrestore(&bp->lock, flags);
disable_irq_wake(bp->queues[0].irq);
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH net v2 2/2] net: macb: Protect access to net_device::ip_ptr with RCU lock
2026-03-18 6:36 [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used Kevin Hao
2026-03-18 6:36 ` [PATCH net v2 1/2] net: macb: Move devm_{free,request}_irq() out of spin lock area Kevin Hao
@ 2026-03-18 6:36 ` Kevin Hao
2026-03-18 9:57 ` Théo Lebrun
2026-03-21 1:30 ` [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used patchwork-bot+netdevbpf
2 siblings, 1 reply; 5+ messages in thread
From: Kevin Hao @ 2026-03-18 6:36 UTC (permalink / raw)
To: netdev
Cc: Nicolas Ferre, Claudiu Beznea, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Vineeth Karumanchi,
Harini Katakam, Théo Lebrun, Kevin Hao, stable
Access to net_device::ip_ptr and its associated members must be
protected by an RCU lock. Since we are modifying this piece of code,
let's also move it to execute only when WAKE_ARP is enabled.
To minimize the duration of the RCU lock, a local variable is used to
temporarily store the IP address. This change resolves the following
RCU check warning:
WARNING: suspicious RCU usage
7.0.0-rc3-next-20260310-yocto-standard+ #122 Not tainted
-----------------------------
drivers/net/ethernet/cadence/macb_main.c:5944 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/518:
#0: ffff000803ab1408 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0xf8/0x368
#1: ffff0008090bf088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0xbc/0x1c8
#2: ffff00080098d588 (kn->active#70){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xcc/0x1c8
#3: ffff800081c84888 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x1ec/0x290
#4: ffff0008009ba0f8 (&dev->mutex){....}-{4:4}, at: device_suspend+0x118/0x4f0
stack backtrace:
CPU: 3 UID: 0 PID: 518 Comm: rtcwake Not tainted 7.0.0-rc3-next-20260310-yocto-standard+ #122 PREEMPT
Hardware name: ZynqMP ZCU102 Rev1.1 (DT)
Call trace:
show_stack+0x24/0x38 (C)
__dump_stack+0x28/0x38
dump_stack_lvl+0x64/0x88
dump_stack+0x18/0x24
lockdep_rcu_suspicious+0x134/0x1d8
macb_suspend+0xd8/0x4c0
device_suspend+0x218/0x4f0
dpm_suspend+0x244/0x3a0
dpm_suspend_start+0x50/0x78
suspend_devices_and_enter+0xec/0x560
pm_suspend+0x194/0x290
state_store+0x110/0x158
kobj_attr_store+0x1c/0x30
sysfs_kf_write+0xa8/0xd0
kernfs_fop_write_iter+0x11c/0x1c8
vfs_write+0x248/0x368
ksys_write+0x7c/0xf8
__arm64_sys_write+0x28/0x40
invoke_syscall+0x4c/0xe8
el0_svc_common+0x98/0xf0
do_el0_svc+0x28/0x40
el0_svc+0x54/0x1e0
el0t_64_sync_handler+0x84/0x130
el0t_64_sync+0x198/0x1a0
Fixes: 0cb8de39a776 ("net: macb: Add ARP support to WOL")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Cc: stable@vger.kernel.org
---
drivers/net/ethernet/cadence/macb_main.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 2d4304331e297accd91ab48813a9bd4722ce72dc..9856764402b17397928d0a61da61865a3b10484f 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -5909,9 +5909,9 @@ static int __maybe_unused macb_suspend(struct device *dev)
struct macb_queue *queue;
struct in_device *idev;
unsigned long flags;
+ u32 tmp, ifa_local;
unsigned int q;
int err;
- u32 tmp;
if (!device_may_wakeup(&bp->dev->dev))
phy_exit(bp->phy);
@@ -5920,14 +5920,21 @@ static int __maybe_unused macb_suspend(struct device *dev)
return 0;
if (bp->wol & MACB_WOL_ENABLED) {
- /* Check for IP address in WOL ARP mode */
- idev = __in_dev_get_rcu(bp->dev);
- if (idev)
- ifa = rcu_dereference(idev->ifa_list);
- if ((bp->wolopts & WAKE_ARP) && !ifa) {
- netdev_err(netdev, "IP address not assigned as required by WoL walk ARP\n");
- return -EOPNOTSUPP;
+ if (bp->wolopts & WAKE_ARP) {
+ /* Check for IP address in WOL ARP mode */
+ rcu_read_lock();
+ idev = __in_dev_get_rcu(bp->dev);
+ if (idev)
+ ifa = rcu_dereference(idev->ifa_list);
+ if (!ifa) {
+ rcu_read_unlock();
+ netdev_err(netdev, "IP address not assigned as required by WoL walk ARP\n");
+ return -EOPNOTSUPP;
+ }
+ ifa_local = be32_to_cpu(ifa->ifa_local);
+ rcu_read_unlock();
}
+
spin_lock_irqsave(&bp->lock, flags);
/* Disable Tx and Rx engines before disabling the queues,
@@ -5966,7 +5973,7 @@ static int __maybe_unused macb_suspend(struct device *dev)
if (bp->wolopts & WAKE_ARP) {
tmp |= MACB_BIT(ARP);
/* write IP address into register */
- tmp |= MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local));
+ tmp |= MACB_BFEXT(IP, ifa_local);
}
spin_unlock_irqrestore(&bp->lock, flags);
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used
2026-03-18 6:36 [PATCH net v2 0/2] net: macb: Fix two lock warnings when WOL is used Kevin Hao
2026-03-18 6:36 ` [PATCH net v2 1/2] net: macb: Move devm_{free,request}_irq() out of spin lock area Kevin Hao
2026-03-18 6:36 ` [PATCH net v2 2/2] net: macb: Protect access to net_device::ip_ptr with RCU lock Kevin Hao
@ 2026-03-21 1:30 ` patchwork-bot+netdevbpf
2 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2026-03-21 1:30 UTC (permalink / raw)
To: Kevin Hao
Cc: netdev, nicolas.ferre, claudiu.beznea, andrew+netdev, davem,
edumazet, kuba, pabeni, vineeth.karumanchi, harini.katakam,
theo.lebrun, stable
Hello:
This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:
On Wed, 18 Mar 2026 14:36:57 +0800 you wrote:
> Hi,
>
> This patch series addresses two lock warnings that occur when using WOL as a
> wakeup source on my AMD ZynqMP board.
>
> ---
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
> Cc: Andrew Lunn <andrew+netdev@lunn.ch>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Vineeth Karumanchi <vineeth.karumanchi@amd.com>
> Cc: Harini Katakam <harini.katakam@amd.com>
> Cc: Théo Lebrun <theo.lebrun@bootlin.com>
>
> [...]
Here is the summary with links:
- [net,v2,1/2] net: macb: Move devm_{free,request}_irq() out of spin lock area
https://git.kernel.org/netdev/net/c/317e49358ebb
- [net,v2,2/2] net: macb: Protect access to net_device::ip_ptr with RCU lock
https://git.kernel.org/netdev/net/c/baa35a698cea
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 5+ messages in thread