Re: [PATCH net v4] igb: Allocate MSI-X vector when testing

[Maciej Fijalkowski]

On Fri, Nov 25, 2022 at 10:30:31PM +0900, Akihiko Odaki wrote:
> Without this change, the interrupt test fail with MSI-X environment:
> 
> $ sudo ethtool -t enp0s2 offline
> [   43.921783] igb 0000:00:02.0: offline testing starting
> [   44.855824] igb 0000:00:02.0 enp0s2: igb: enp0s2 NIC Link is Down
> [   44.961249] igb 0000:00:02.0 enp0s2: igb: enp0s2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
> [   51.272202] igb 0000:00:02.0: testing shared interrupt
> [   56.996975] igb 0000:00:02.0 enp0s2: igb: enp0s2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
> The test result is FAIL
> The test extra info:
> Register test  (offline)	 0
> Eeprom test    (offline)	 0
> Interrupt test (offline)	 4
> Loopback test  (offline)	 0
> Link test   (on/offline)	 0
> 
> Here, "4" means an expected interrupt was not delivered.
> 
> To fix this, route IRQs correctly to the first MSI-X vector by setting
> IVAR_MISC. Also, set bit 0 of EIMS so that the vector will not be
> masked. The interrupt test now runs properly with this change:
> 
> $ sudo ethtool -t enp0s2 offline
> [   42.762985] igb 0000:00:02.0: offline testing starting
> [   50.141967] igb 0000:00:02.0: testing shared interrupt
> [   56.163957] igb 0000:00:02.0 enp0s2: igb: enp0s2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
> The test result is PASS
> The test extra info:
> Register test  (offline)	 0
> Eeprom test    (offline)	 0
> Interrupt test (offline)	 0
> Loopback test  (offline)	 0
> Link test   (on/offline)	 0
> 
> Fixes: 4eefa8f01314 ("igb: add single vector msi-x testing to interrupt test")
> Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>

> ---
> V3 -> V4: Added Fixes: tag
> 
>  drivers/net/ethernet/intel/igb/igb_ethtool.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> index e5f3e7680dc6..ff911af16a4b 100644
> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> @@ -1413,6 +1413,8 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
>  			*data = 1;
>  			return -1;
>  		}
> +		wr32(E1000_IVAR_MISC, E1000_IVAR_VALID << 8);
> +		wr32(E1000_EIMS, BIT(0));
>  	} else if (adapter->flags & IGB_FLAG_HAS_MSI) {
>  		shared_int = false;
>  		if (request_irq(irq,
> -- 
> 2.38.1
>