by Vladimir Oltean

[permalink] [raw]

Subject: Re: [PATCH net-next v1 21/21] net: dsa: Move devlink registration to be last devlink command

Hi Leon,

On Sat, Sep 25, 2021 at 02:23:01PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <[email protected]>
>
> This change prevents from users to access device before devlink
> is fully configured.
>
> Signed-off-by: Leon Romanovsky <[email protected]>
> ---
> net/dsa/dsa2.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
> index a020339e1973..8ca6a1170c9d 100644
> --- a/net/dsa/dsa2.c
> +++ b/net/dsa/dsa2.c
> @@ -848,7 +848,6 @@ static int dsa_switch_setup(struct dsa_switch *ds)
> dl_priv = devlink_priv(ds->devlink);
> dl_priv->ds = ds;
>
> - devlink_register(ds->devlink);
> /* Setup devlink port instances now, so that the switch
> * setup() can register regions etc, against the ports
> */
> @@ -874,8 +873,6 @@ static int dsa_switch_setup(struct dsa_switch *ds)
> if (err)
> goto teardown;
>
> - devlink_params_publish(ds->devlink);
> -
> if (!ds->slave_mii_bus && ds->ops->phy_read) {
> ds->slave_mii_bus = mdiobus_alloc();
> if (!ds->slave_mii_bus) {
> @@ -891,7 +888,7 @@ static int dsa_switch_setup(struct dsa_switch *ds)
> }
>
> ds->setup = true;
> -
> + devlink_register(ds->devlink);
> return 0;
>
> free_slave_mii_bus:
> @@ -906,7 +903,6 @@ static int dsa_switch_setup(struct dsa_switch *ds)
> list_for_each_entry(dp, &ds->dst->ports, list)
> if (dp->ds == ds)
> dsa_port_devlink_teardown(dp);
> - devlink_unregister(ds->devlink);
> devlink_free(ds->devlink);
> ds->devlink = NULL;
> return err;
> @@ -919,6 +915,9 @@ static void dsa_switch_teardown(struct dsa_switch *ds)
> if (!ds->setup)
> return;
>
> + if (ds->devlink)
> + devlink_unregister(ds->devlink);
> +
> if (ds->slave_mii_bus && ds->ops->phy_read) {
> mdiobus_unregister(ds->slave_mii_bus);
> mdiobus_free(ds->slave_mii_bus);
> @@ -934,7 +933,6 @@ static void dsa_switch_teardown(struct dsa_switch *ds)
> list_for_each_entry(dp, &ds->dst->ports, list)
> if (dp->ds == ds)
> dsa_port_devlink_teardown(dp);
> - devlink_unregister(ds->devlink);
> devlink_free(ds->devlink);
> ds->devlink = NULL;
> }
> --
> 2.31.1
>

Sorry, I did not have time to review/test this change earlier.
I now see this WARN_ON being triggered when I boot a board:

[ 6.731180] WARNING: CPU: 1 PID: 79 at net/core/devlink.c:5158 devlink_nl_region_notify+0xa8/0xc0
[ 6.740123] Modules linked in:
[ 6.743217] CPU: 1 PID: 79 Comm: kworker/u4:2 Tainted: G W 5.15.0-rc2-07010-ga9b9500ffaac-dirty #876
[ 6.759155] Workqueue: events_unbound deferred_probe_work_func
[ 6.765048] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 6.772060] pc : devlink_nl_region_notify+0xa8/0xc0
[ 6.776978] lr : devlink_nl_region_notify+0x3c/0xc0
[ 6.781893] sp : ffff8000108b38b0
[ 6.785235] x29: ffff8000108b38b0 x28: ffff6fce86e53780 x27: ffff6fce86e525c8
[ 6.792453] x26: ffff6fce86e69b00 x25: ffff6fce86e57600 x24: 0000000000017528
[ 6.799668] x23: 0000000000000001 x22: ffff6fce86e57400 x21: 000000000000002c
[ 6.806883] x20: 0000000000000000 x19: ffff6fce86e69b00 x18: 00000000fffffff8
[ 6.814098] x17: 000000000000013f x16: 000000000000017f x15: ffffffffffffffff
[ 6.821313] x14: ffffff0000000000 x13: ffffffffffffffff x12: 000000000000000b
[ 6.828528] x11: ffffc1141c2fce38 x10: 0000000000000005 x9 : 659dd6f91764a956
[ 6.835742] x8 : ffff6fce851ce100 x7 : ffffc1141c6bf000 x6 : 000000003020805e
[ 6.842956] x5 : 00ffffffffffffff x4 : ffffaebaddb5a000 x3 : 0000000000000000
[ 6.850169] x2 : 0000000000000000 x1 : ffff6fce851ce100 x0 : 0000000000000000
[ 6.857383] Call trace:
[ 6.859854] devlink_nl_region_notify+0xa8/0xc0
[ 6.864422] devlink_region_create+0x110/0x150
[ 6.868902] dsa_devlink_region_create+0x14/0x20
[ 6.873563] sja1105_devlink_setup+0x54/0xa0
[ 6.877871] sja1105_setup+0x144/0x1390
[ 6.881742] dsa_register_switch+0x978/0x1010
[ 6.886139] sja1105_probe+0x628/0x644
[ 6.889920] spi_probe+0x84/0xe4
[ 6.893180] really_probe.part.0+0x9c/0x31c
[ 6.897402] __driver_probe_device+0x98/0x144
[ 6.901797] driver_probe_device+0xc8/0x160
[ 6.906019] __device_attach_driver+0xb8/0x120
[ 6.910501] bus_for_each_drv+0x78/0xd0
[ 6.914373] __device_attach+0xd8/0x180
[ 6.918243] device_initial_probe+0x14/0x20
[ 6.922466] bus_probe_device+0x9c/0xa4
[ 6.926337] deferred_probe_work_func+0x88/0xc4
[ 6.930906] process_one_work+0x288/0x6f0
[ 6.934952] worker_thread+0x74/0x470
[ 6.938646] kthread+0x160/0x170
[ 6.941909] ret_from_fork+0x10/0x20
[ 6.945519] irq event stamp: 64656