Re: [PATCH net v2 1/3] net: txgbe: request MISC IRQ in ndo_open

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

On Wed, Jun 25, 2025 at 05:22:27PM +0800, Jiawen Wu wrote:
> On Wed, Jun 25, 2025 4:53 PM, Michal Swiatkowski wrote:
> > On Tue, Jun 24, 2025 at 04:56:32PM +0800, Jiawen Wu wrote:
> > > Move the creating of irq_domain for MISC IRQ from .probe to .ndo_open,
> > > and free it in .ndo_stop, to maintain consistency with the queue IRQs.
> > > This it for subsequent adjustments to the IRQ vectors.
> > >
> > > Fixes: aefd013624a1 ("net: txgbe: use irq_domain for interrupt controller")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
> > > ---
> > >  .../net/ethernet/wangxun/txgbe/txgbe_irq.c    |  2 +-
> > >  .../net/ethernet/wangxun/txgbe/txgbe_main.c   | 22 +++++++++----------
> > >  2 files changed, 11 insertions(+), 13 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
> > > index 20b9a28bcb55..dc468053bdf8 100644
> > > --- a/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
> > > +++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
> > > @@ -78,7 +78,6 @@ int txgbe_request_queue_irqs(struct wx *wx)
> > >  		free_irq(wx->msix_q_entries[vector].vector,
> > >  			 wx->q_vector[vector]);
> > >  	}
> > > -	wx_reset_interrupt_capability(wx);
> > >  	return err;
> > >  }
> > >
> > > @@ -211,6 +210,7 @@ void txgbe_free_misc_irq(struct txgbe *txgbe)
> > >  	free_irq(txgbe->link_irq, txgbe);
> > >  	free_irq(txgbe->misc.irq, txgbe);
> > >  	txgbe_del_irq_domain(txgbe);
> > > +	txgbe->wx->misc_irq_domain = false;
> > >  }
> > >
> > >  int txgbe_setup_misc_irq(struct txgbe *txgbe)
> > > diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> > > index f3d2778b8e35..a5867f3c93fc 100644
> > > --- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> > > +++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> > > @@ -458,10 +458,14 @@ static int txgbe_open(struct net_device *netdev)
> > >
> > >  	wx_configure(wx);
> > >
> > > -	err = txgbe_request_queue_irqs(wx);
> > > +	err = txgbe_setup_misc_irq(wx->priv);
> > 
> > Don't you need misc interrupt before ndo_open is called? I wonder if it
> > won't be simpler to always use last index (8) for misc irq. Is it
> > possible? I mean, use 8 event if the number of queues is lower than 8.
> > If yes you can drop this patch and hardcode misc interrupts on index 8.
> > 
> > [...]
> > 
> > BTW, assuming you can't always use last index, the patch looks fine.
> 
> Cannot always use index (8). Because the max RSS index is 63 for TXGBE,
> but 8 for NGBE. This hardware limitation is only for NGBE. And index (8)
> cannot be used by PF when SRIOV is enabled on NGBE.
> 
> In fact, the misc interrupt is only used when the device is opened.
> 
> 

Ok, thanks
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>