Re: [PATCH] net: ethernet: ti: cpsw: fix ASSERT_RTNL() warning during resume

[Dave Gerlach]

On 11/29/2016 06:18 PM, Ivan Khoronzhuk wrote:
> On Tue, Nov 29, 2016 at 04:27:03PM -0600, Grygorii Strashko wrote:
> > netif_set_real_num_tx/rx_queues() are required to be called with rtnl_lock
> > taken, otherwise ASSERT_RTNL() warning will be triggered - which happens
> > now during System resume from suspend:
> > cpsw_resume()
> > |- cpsw_ndo_open()
> >   |- netif_set_real_num_tx/rx_queues()
> >      |- ASSERT_RTNL();
> >
> > Hence, fix it by surrounding cpsw_ndo_open() by rtnl_lock/unlock() calls.
> >
> > Cc: Dave Gerlach <d-gerlach@xxxxxx>
> > Cc: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> > Fixes: commit e05107e6b747 ("net: ethernet: ti: cpsw: add multi queue support")
> > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Reviewed-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>

Tested-by: Dave Gerlach <d-gerlach@xxxxxx>

> > ---
> >  drivers/net/ethernet/ti/cpsw.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> > index ae1ec6a..fd6c03b 100644
> > --- a/drivers/net/ethernet/ti/cpsw.c
> > +++ b/drivers/net/ethernet/ti/cpsw.c
> > @@ -2944,6 +2944,8 @@ static int cpsw_resume(struct device *dev)
> >  	/* Select default pin state */
> >  	pinctrl_pm_select_default_state(dev);
> >
> > +	/* shut up ASSERT_RTNL() warning in netif_set_real_num_tx/rx_queues */
> > +	rtnl_lock();
> >  	if (cpsw->data.dual_emac) {
> >  		int i;
> >
> > @@ -2955,6 +2957,8 @@ static int cpsw_resume(struct device *dev)
> >  		if (netif_running(ndev))
> >  			cpsw_ndo_open(ndev);
> >  	}
> > +	rtnl_unlock();
> > +
> >  	return 0;
> >  }
> >  #endif
> > --
> > 2.10.1