Fix the suspend path by ensuring the rtnl lock is held where required.
Calls to ravb_open, ravb_close and wol operations must be performed under
the rtnl lock to prevent conflicts with ongoing ndo operations.
Without this fix, the following warning is triggered:
[ 39.032969] =============================
[ 39.032983] WARNING: suspicious RCU usage
[ 39.033019] -----------------------------
[ 39.033033] drivers/net/phy/phy_device.c:2004 suspicious
rcu_dereference_protected() usage!
...
[ 39.033597] stack backtrace:
[ 39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
[ 39.033623] Hardware name: Renesas SMARC EVK version 2 based on
r9a08g045s33 (DT)
[ 39.033628] Call trace:
[ 39.033633] show_stack+0x14/0x1c (C)
[ 39.033652] dump_stack_lvl+0xb4/0xc4
[ 39.033664] dump_stack+0x14/0x1c
[ 39.033671] lockdep_rcu_suspicious+0x16c/0x22c
[ 39.033682] phy_detach+0x160/0x190
[ 39.033694] phy_disconnect+0x40/0x54
[ 39.033703] ravb_close+0x6c/0x1cc
[ 39.033714] ravb_suspend+0x48/0x120
[ 39.033721] dpm_run_callback+0x4c/0x14c
[ 39.033731] device_suspend+0x11c/0x4dc
[ 39.033740] dpm_suspend+0xdc/0x214
[ 39.033748] dpm_suspend_start+0x48/0x60
[ 39.033758] suspend_devices_and_enter+0x124/0x574
[ 39.033769] pm_suspend+0x1ac/0x274
[ 39.033778] state_store+0x88/0x124
[ 39.033788] kobj_attr_store+0x14/0x24
[ 39.033798] sysfs_kf_write+0x48/0x6c
[ 39.033808] kernfs_fop_write_iter+0x118/0x1a8
[ 39.033817] vfs_write+0x27c/0x378
[ 39.033825] ksys_write+0x64/0xf4
[ 39.033833] __arm64_sys_write+0x18/0x20
[ 39.033841] invoke_syscall+0x44/0x104
[ 39.033852] el0_svc_common.constprop.0+0xb4/0xd4
[ 39.033862] do_el0_svc+0x18/0x20
[ 39.033870] el0_svc+0x3c/0xf0
[ 39.033880] el0t_64_sync_handler+0xc0/0xc4
[ 39.033888] el0t_64_sync+0x154/0x158
[ 39.041274] ravb 11c30000.ethernet eth0: Link is Down
Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
drivers/net/ethernet/renesas/ravb_main.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index bc395294a32d..2c6d8e4966c3 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -3217,10 +3217,15 @@ static int ravb_suspend(struct device *dev)
netif_device_detach(ndev);
- if (priv->wol_enabled)
- return ravb_wol_setup(ndev);
+ rtnl_lock();
+ if (priv->wol_enabled) {
+ ret = ravb_wol_setup(ndev);
+ rtnl_unlock();
+ return ret;
+ }
ret = ravb_close(ndev);
+ rtnl_unlock();
if (ret)
return ret;
@@ -3245,19 +3250,25 @@ static int ravb_resume(struct device *dev)
if (!netif_running(ndev))
return 0;
+ rtnl_lock();
/* If WoL is enabled restore the interface. */
if (priv->wol_enabled) {
ret = ravb_wol_restore(ndev);
- if (ret)
+ if (ret) {
+ rtnl_unlock();
return ret;
+ }
} else {
ret = pm_runtime_force_resume(dev);
- if (ret)
+ if (ret) {
+ rtnl_unlock();
return ret;
+ }
}
/* Reopening the interface will restore the device to the working state. */
ret = ravb_open(ndev);
+ rtnl_unlock();
if (ret < 0)
goto out_rpm_put;
--
2.34.1Hi, Kory,
On 22.01.2025 18:19, Kory Maincent wrote:
> Fix the suspend path by ensuring the rtnl lock is held where required.
> Calls to ravb_open, ravb_close and wol operations must be performed under
> the rtnl lock to prevent conflicts with ongoing ndo operations.
>
> Without this fix, the following warning is triggered:
> [ 39.032969] =============================
> [ 39.032983] WARNING: suspicious RCU usage
> [ 39.033019] -----------------------------
> [ 39.033033] drivers/net/phy/phy_device.c:2004 suspicious
> rcu_dereference_protected() usage!
> ...
> [ 39.033597] stack backtrace:
> [ 39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
> 6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
> [ 39.033623] Hardware name: Renesas SMARC EVK version 2 based on
> r9a08g045s33 (DT)
> [ 39.033628] Call trace:
> [ 39.033633] show_stack+0x14/0x1c (C)
> [ 39.033652] dump_stack_lvl+0xb4/0xc4
> [ 39.033664] dump_stack+0x14/0x1c
> [ 39.033671] lockdep_rcu_suspicious+0x16c/0x22c
> [ 39.033682] phy_detach+0x160/0x190
> [ 39.033694] phy_disconnect+0x40/0x54
> [ 39.033703] ravb_close+0x6c/0x1cc
> [ 39.033714] ravb_suspend+0x48/0x120
> [ 39.033721] dpm_run_callback+0x4c/0x14c
> [ 39.033731] device_suspend+0x11c/0x4dc
> [ 39.033740] dpm_suspend+0xdc/0x214
> [ 39.033748] dpm_suspend_start+0x48/0x60
> [ 39.033758] suspend_devices_and_enter+0x124/0x574
> [ 39.033769] pm_suspend+0x1ac/0x274
> [ 39.033778] state_store+0x88/0x124
> [ 39.033788] kobj_attr_store+0x14/0x24
> [ 39.033798] sysfs_kf_write+0x48/0x6c
> [ 39.033808] kernfs_fop_write_iter+0x118/0x1a8
> [ 39.033817] vfs_write+0x27c/0x378
> [ 39.033825] ksys_write+0x64/0xf4
> [ 39.033833] __arm64_sys_write+0x18/0x20
> [ 39.033841] invoke_syscall+0x44/0x104
> [ 39.033852] el0_svc_common.constprop.0+0xb4/0xd4
> [ 39.033862] do_el0_svc+0x18/0x20
> [ 39.033870] el0_svc+0x3c/0xf0
> [ 39.033880] el0t_64_sync_handler+0xc0/0xc4
> [ 39.033888] el0t_64_sync+0x154/0x158
> [ 39.041274] ravb 11c30000.ethernet eth0: Link is Down
>
> Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
> Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
I've test it. Looks good.
Thank you for your patch. However, I think this could be simplified. The
locking scheme looks complicated to me. E.g., this one works too:
diff --git a/drivers/net/ethernet/renesas/ravb_main.c
b/drivers/net/ethernet/renesas/ravb_main.c
index bc395294a32d..cfe4f0f364f3 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -3217,10 +3217,16 @@ static int ravb_suspend(struct device *dev)
netif_device_detach(ndev);
- if (priv->wol_enabled)
- return ravb_wol_setup(ndev);
+ if (priv->wol_enabled) {
+ rtnl_lock();
+ ret = ravb_wol_setup(ndev);
+ rtnl_unlock();
+ return ret;
+ }
+ rtnl_lock();
ret = ravb_close(ndev);
+ rtnl_unlock();
if (ret)
return ret;
@@ -3247,7 +3253,9 @@ static int ravb_resume(struct device *dev)
/* If WoL is enabled restore the interface. */
if (priv->wol_enabled) {
+ rtnl_lock();
ret = ravb_wol_restore(ndev);
+ rtnl_unlock();
if (ret)
return ret;
} else {
@@ -3257,7 +3265,9 @@ static int ravb_resume(struct device *dev)
}
/* Reopening the interface will restore the device to the working
state. */
+ rtnl_lock();
ret = ravb_open(ndev);
+ rtnl_unlock();
if (ret < 0)
goto out_rpm_put;
> ---
> drivers/net/ethernet/renesas/ravb_main.c | 19 +++++++++++++++----
> 1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index bc395294a32d..2c6d8e4966c3 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -3217,10 +3217,15 @@ static int ravb_suspend(struct device *dev)
>
> netif_device_detach(ndev);
>
> - if (priv->wol_enabled)
> - return ravb_wol_setup(ndev);
> + rtnl_lock();
> + if (priv->wol_enabled) {
> + ret = ravb_wol_setup(ndev);
> + rtnl_unlock();
> + return ret;
> + }
>
> ret = ravb_close(ndev);
> + rtnl_unlock();
> if (ret)
> return ret;
>
> @@ -3245,19 +3250,25 @@ static int ravb_resume(struct device *dev)
> if (!netif_running(ndev))
> return 0;
>
> + rtnl_lock();
> /* If WoL is enabled restore the interface. */
> if (priv->wol_enabled) {
> ret = ravb_wol_restore(ndev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
> + }
> } else {
> ret = pm_runtime_force_resume(dev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
> + }
> }
>
> /* Reopening the interface will restore the device to the working state. */
> ret = ravb_open(ndev);
> + rtnl_unlock();
> if (ret < 0)
> goto out_rpm_put;
>
>
On Thu, 23 Jan 2025 13:33:30 +0200
Claudiu Beznea <claudiu.beznea@tuxon.dev> wrote:
> Hi, Kory,
>
> On 22.01.2025 18:19, Kory Maincent wrote:
> > Fix the suspend path by ensuring the rtnl lock is held where required.
> > Calls to ravb_open, ravb_close and wol operations must be performed under
> > the rtnl lock to prevent conflicts with ongoing ndo operations.
>
> I've test it. Looks good.
>
> Thank you for your patch. However, I think this could be simplified. The
> locking scheme looks complicated to me. E.g., this one works too:
>
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> b/drivers/net/ethernet/renesas/ravb_main.c
> index bc395294a32d..cfe4f0f364f3 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -3217,10 +3217,16 @@ static int ravb_suspend(struct device *dev)
>
> netif_device_detach(ndev);
>
> - if (priv->wol_enabled)
> - return ravb_wol_setup(ndev);
> + if (priv->wol_enabled) {
> + rtnl_lock();
> + ret = ravb_wol_setup(ndev);
> + rtnl_unlock();
> + return ret;
> + }
What happen if wol_enabled flag changes it state between the rtnl_lock and the
if condition? We will be in the wrong path.
Regards,
--
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
On 23.01.2025 16:08, Kory Maincent wrote:
> On Thu, 23 Jan 2025 13:33:30 +0200
> Claudiu Beznea <claudiu.beznea@tuxon.dev> wrote:
>
>> Hi, Kory,
>>
>> On 22.01.2025 18:19, Kory Maincent wrote:
>>> Fix the suspend path by ensuring the rtnl lock is held where required.
>>> Calls to ravb_open, ravb_close and wol operations must be performed under
>>> the rtnl lock to prevent conflicts with ongoing ndo operations.
>
>>
>> I've test it. Looks good.
>>
>> Thank you for your patch. However, I think this could be simplified. The
>> locking scheme looks complicated to me. E.g., this one works too:
>>
>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
>> b/drivers/net/ethernet/renesas/ravb_main.c
>> index bc395294a32d..cfe4f0f364f3 100644
>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>> @@ -3217,10 +3217,16 @@ static int ravb_suspend(struct device *dev)
>>
>> netif_device_detach(ndev);
>>
>> - if (priv->wol_enabled)
>> - return ravb_wol_setup(ndev);
>> + if (priv->wol_enabled) {
>> + rtnl_lock();
>> + ret = ravb_wol_setup(ndev);
>> + rtnl_unlock();
>> + return ret;
>> + }
>
> What happen if wol_enabled flag changes it state between the rtnl_lock and the
> if condition? We will be in the wrong path.
wol_enabled flag can't change in this suspend phase. The user space tasks
are fronzen when ravb_suspend() is called.
Thank you,
Claudiu
>
> Regards,
On Thu, 23 Jan 2025 16:17:58 +0200
Claudiu Beznea <claudiu.beznea@tuxon.dev> wrote:
> On 23.01.2025 16:08, Kory Maincent wrote:
> > On Thu, 23 Jan 2025 13:33:30 +0200
> > Claudiu Beznea <claudiu.beznea@tuxon.dev> wrote:
> >
> >> Hi, Kory,
> >>
> >> On 22.01.2025 18:19, Kory Maincent wrote:
> [...]
> >
> >>
> >> I've test it. Looks good.
> >>
> >> Thank you for your patch. However, I think this could be simplified. The
> >> locking scheme looks complicated to me. E.g., this one works too:
> >>
> >> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> >> b/drivers/net/ethernet/renesas/ravb_main.c
> >> index bc395294a32d..cfe4f0f364f3 100644
> >> --- a/drivers/net/ethernet/renesas/ravb_main.c
> >> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> >> @@ -3217,10 +3217,16 @@ static int ravb_suspend(struct device *dev)
> >>
> >> netif_device_detach(ndev);
> >>
> >> - if (priv->wol_enabled)
> >> - return ravb_wol_setup(ndev);
> >> + if (priv->wol_enabled) {
> >> + rtnl_lock();
> >> + ret = ravb_wol_setup(ndev);
> >> + rtnl_unlock();
> >> + return ret;
> >> + }
> >
> > What happen if wol_enabled flag changes it state between the rtnl_lock and
> > the if condition? We will be in the wrong path.
>
> wol_enabled flag can't change in this suspend phase. The user space tasks
> are fronzen when ravb_suspend() is called.
Oh ok, I don't now the suspend path but if it can't conflict we can got for your
proposition.
Regards,
--
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
On 22/01/2025 16:19, Kory Maincent wrote:
> Fix the suspend path by ensuring the rtnl lock is held where required.
> Calls to ravb_open, ravb_close and wol operations must be performed under
> the rtnl lock to prevent conflicts with ongoing ndo operations.
>
> Without this fix, the following warning is triggered:
> [ 39.032969] =============================
> [ 39.032983] WARNING: suspicious RCU usage
> [ 39.033019] -----------------------------
> [ 39.033033] drivers/net/phy/phy_device.c:2004 suspicious
> rcu_dereference_protected() usage!
> ...
> [ 39.033597] stack backtrace:
> [ 39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
> 6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
> [ 39.033623] Hardware name: Renesas SMARC EVK version 2 based on
> r9a08g045s33 (DT)
> [ 39.033628] Call trace:
> [ 39.033633] show_stack+0x14/0x1c (C)
> [ 39.033652] dump_stack_lvl+0xb4/0xc4
> [ 39.033664] dump_stack+0x14/0x1c
> [ 39.033671] lockdep_rcu_suspicious+0x16c/0x22c
> [ 39.033682] phy_detach+0x160/0x190
> [ 39.033694] phy_disconnect+0x40/0x54
> [ 39.033703] ravb_close+0x6c/0x1cc
> [ 39.033714] ravb_suspend+0x48/0x120
> [ 39.033721] dpm_run_callback+0x4c/0x14c
> [ 39.033731] device_suspend+0x11c/0x4dc
> [ 39.033740] dpm_suspend+0xdc/0x214
> [ 39.033748] dpm_suspend_start+0x48/0x60
> [ 39.033758] suspend_devices_and_enter+0x124/0x574
> [ 39.033769] pm_suspend+0x1ac/0x274
> [ 39.033778] state_store+0x88/0x124
> [ 39.033788] kobj_attr_store+0x14/0x24
> [ 39.033798] sysfs_kf_write+0x48/0x6c
> [ 39.033808] kernfs_fop_write_iter+0x118/0x1a8
> [ 39.033817] vfs_write+0x27c/0x378
> [ 39.033825] ksys_write+0x64/0xf4
> [ 39.033833] __arm64_sys_write+0x18/0x20
> [ 39.033841] invoke_syscall+0x44/0x104
> [ 39.033852] el0_svc_common.constprop.0+0xb4/0xd4
> [ 39.033862] do_el0_svc+0x18/0x20
> [ 39.033870] el0_svc+0x3c/0xf0
> [ 39.033880] el0t_64_sync_handler+0xc0/0xc4
> [ 39.033888] el0t_64_sync+0x154/0x158
> [ 39.041274] ravb 11c30000.ethernet eth0: Link is Down
>
> Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
> Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
I think we can simplify ravb_suspend() and ravb_resume() with a bit of
refactoring, but that can be done as a follow-up.
Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
--
Paul Barker
Hello!
My Cogent Embedded tenure is long over, so I dropped my old email... :-)
On 1/22/25 7:19 PM, Kory Maincent wrote:
> Fix the suspend path by ensuring the rtnl lock is held where required.
Maybe suspend/resume path (the same w/the subject)?
> Calls to ravb_open, ravb_close and wol operations must be performed under
> the rtnl lock to prevent conflicts with ongoing ndo operations.
[...]
> Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
> Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
FWIW:
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
[...]
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index bc395294a32d..2c6d8e4966c3 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
[...]
> @@ -3245,19 +3250,25 @@ static int ravb_resume(struct device *dev)
> if (!netif_running(ndev))
> return 0;
>
> + rtnl_lock();
> /* If WoL is enabled restore the interface. */
> if (priv->wol_enabled) {
> ret = ravb_wol_restore(ndev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
> + }
> } else {
> ret = pm_runtime_force_resume(dev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
Hm, are you sure we need to have rtnl_lock around pm_runtime_force_resume() too?
[...]
MBR, Sergey
On 1/22/25 9:33 PM, Sergey Shtylyov wrote:
[...]
>> Fix the suspend path by ensuring the rtnl lock is held where required.
>
> Maybe suspend/resume path (the same w/the subject)?
>
>> Calls to ravb_open, ravb_close and wol operations must be performed under
>> the rtnl lock to prevent conflicts with ongoing ndo operations.
>
> [...]
>
>> Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>> Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
>> Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
>> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
>
> FWIW:
>
> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
>
> [...]
>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>> index bc395294a32d..2c6d8e4966c3 100644
>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> [...]
>> @@ -3245,19 +3250,25 @@ static int ravb_resume(struct device *dev)
>> if (!netif_running(ndev))
>> return 0;
>>
>> + rtnl_lock();
>> /* If WoL is enabled restore the interface. */
>> if (priv->wol_enabled) {
>> ret = ravb_wol_restore(ndev);
>> - if (ret)
>> + if (ret) {
>> + rtnl_unlock();
>> return ret;
>> + }
>> } else {
>> ret = pm_runtime_force_resume(dev);
>> - if (ret)
>> + if (ret) {
>> + rtnl_unlock();
>> return ret;
>
> Hm, are you sure we need to have rtnl_lock around pm_runtime_force_resume() too?
Anyway, the above *if* statements are needlessly duplicated, I think it's time
that we do away with this! :-)
[...]
MBR, Sergey
Hi Kory,
Thanks for your work.
On 2025-01-22 17:19:28 +0100, Kory Maincent wrote:
> Fix the suspend path by ensuring the rtnl lock is held where required.
> Calls to ravb_open, ravb_close and wol operations must be performed under
> the rtnl lock to prevent conflicts with ongoing ndo operations.
>
> Without this fix, the following warning is triggered:
> [ 39.032969] =============================
> [ 39.032983] WARNING: suspicious RCU usage
> [ 39.033019] -----------------------------
> [ 39.033033] drivers/net/phy/phy_device.c:2004 suspicious
> rcu_dereference_protected() usage!
> ...
> [ 39.033597] stack backtrace:
> [ 39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
> 6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
> [ 39.033623] Hardware name: Renesas SMARC EVK version 2 based on
> r9a08g045s33 (DT)
> [ 39.033628] Call trace:
> [ 39.033633] show_stack+0x14/0x1c (C)
> [ 39.033652] dump_stack_lvl+0xb4/0xc4
> [ 39.033664] dump_stack+0x14/0x1c
> [ 39.033671] lockdep_rcu_suspicious+0x16c/0x22c
> [ 39.033682] phy_detach+0x160/0x190
> [ 39.033694] phy_disconnect+0x40/0x54
> [ 39.033703] ravb_close+0x6c/0x1cc
> [ 39.033714] ravb_suspend+0x48/0x120
> [ 39.033721] dpm_run_callback+0x4c/0x14c
> [ 39.033731] device_suspend+0x11c/0x4dc
> [ 39.033740] dpm_suspend+0xdc/0x214
> [ 39.033748] dpm_suspend_start+0x48/0x60
> [ 39.033758] suspend_devices_and_enter+0x124/0x574
> [ 39.033769] pm_suspend+0x1ac/0x274
> [ 39.033778] state_store+0x88/0x124
> [ 39.033788] kobj_attr_store+0x14/0x24
> [ 39.033798] sysfs_kf_write+0x48/0x6c
> [ 39.033808] kernfs_fop_write_iter+0x118/0x1a8
> [ 39.033817] vfs_write+0x27c/0x378
> [ 39.033825] ksys_write+0x64/0xf4
> [ 39.033833] __arm64_sys_write+0x18/0x20
> [ 39.033841] invoke_syscall+0x44/0x104
> [ 39.033852] el0_svc_common.constprop.0+0xb4/0xd4
> [ 39.033862] do_el0_svc+0x18/0x20
> [ 39.033870] el0_svc+0x3c/0xf0
> [ 39.033880] el0t_64_sync_handler+0xc0/0xc4
> [ 39.033888] el0t_64_sync+0x154/0x158
> [ 39.041274] ravb 11c30000.ethernet eth0: Link is Down
>
> Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
> Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
I need to apply [1] to see the WARNING: suspicious RCU usage splat at
all, I guess there is a WARN_ONCE somewhere. But with this patch applied
the splat is gone when resuming and WoL works.
Tested on R-Car M3N with NFS root on the interface used for WoL.
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
1. [PATCH] gpio: rcar: Use raw_spinlock to protect register access
> ---
> drivers/net/ethernet/renesas/ravb_main.c | 19 +++++++++++++++----
> 1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index bc395294a32d..2c6d8e4966c3 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -3217,10 +3217,15 @@ static int ravb_suspend(struct device *dev)
>
> netif_device_detach(ndev);
>
> - if (priv->wol_enabled)
> - return ravb_wol_setup(ndev);
> + rtnl_lock();
> + if (priv->wol_enabled) {
> + ret = ravb_wol_setup(ndev);
> + rtnl_unlock();
> + return ret;
> + }
>
> ret = ravb_close(ndev);
> + rtnl_unlock();
> if (ret)
> return ret;
>
> @@ -3245,19 +3250,25 @@ static int ravb_resume(struct device *dev)
> if (!netif_running(ndev))
> return 0;
>
> + rtnl_lock();
> /* If WoL is enabled restore the interface. */
> if (priv->wol_enabled) {
> ret = ravb_wol_restore(ndev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
> + }
> } else {
> ret = pm_runtime_force_resume(dev);
> - if (ret)
> + if (ret) {
> + rtnl_unlock();
> return ret;
> + }
> }
>
> /* Reopening the interface will restore the device to the working state. */
> ret = ravb_open(ndev);
> + rtnl_unlock();
> if (ret < 0)
> goto out_rpm_put;
>
>
> --
> 2.34.1
>
--
Kind Regards,
Niklas Söderlund
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