Re: [PATCH v3] igb: Allocate MSI-X vector when testing

From: Akihiko Odaki
Date: Fri Nov 25 2022 - 04:54:02 EST


On 2022/11/25 18:48, Akihiko Odaki wrote:


On 2022/11/24 0:41, Maciej Fijalkowski wrote:
On Wed, Nov 23, 2022 at 10:09:26AM +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:

Much better!


$ 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

Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>

Same comment as on other patch - justify why there is no fixes tag and
specify the tree in subject.

I couldn't identify what commit introduced the problem. Please see:
https://lore.kernel.org/netdev/f2457229-865a-57a0-94a1-c5c63b2f30a5@xxxxxxxxxx/

Sorry, the URL was wrong. The correct URL is:
https://lore.kernel.org/netdev/be5617fe-d332-447a-b836-bec9a6c6d42d@xxxxxxxxxx/

Regards,
Akihiko Odaki


Regards,
Akihiko Odaki


---
  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