| Message ID | 20250122-fix_missing_rtnl_lock_phy_disconnect-v1-1-8cb9f6f88fd1@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Fix missing rtnl lock in suspend path | expand |
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 >
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
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>
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. > > 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,
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,
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;
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(-)