On 23/01/2025 16:58, 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@xxxxxxxxxxxxxx> > Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@xxxxxxxxx/ > Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support") > Reviewed-by: Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx> > Tested-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx> > Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx> > Signed-off-by: Kory Maincent <kory.maincent@xxxxxxxxxxx> > --- > > Changes in v2: > - Move the rtnl_lock before ravb_wol_setup() and and ravb_wol_restore() > instead of before the if condition. > --- > drivers/net/ethernet/renesas/ravb_main.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > 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; > > Please remove Reviewed-by tags when making changes like this in a subsequent version of a patch series, this is no longer the patch I reviewed. I don't like the multiple lock/unlock calls in each function. I think v1 was better, where we take the lock once in each function and then unlock when it is no longer needed or when we're about to return. Thanks, -- Paul Barker
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