Re: [PATCH 4/5] qtest/e1000e|igb: Clear interrupt-cause bits after irq

["Nicholas Piggin" <npiggin@gmail.com>]

On Thu Dec 19, 2024 at 7:00 PM AEST, Akihiko Odaki wrote:
> On 2024/12/18 16:42, Nicholas Piggin wrote:
> > The e1000e and igb tests do not clear the ICR/EICR cause bits (or
> > set auto-clear) on seeing queue interrupts, which inhibits the
> > triggering of a new interrupt.
> > 
> > Fix this by clearing the cause bits, and verify that the expected
> > cause bit was set.
> > 
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> > Cc: Dmitry Fleytman <dmitry.fleytman@gmail.com>
> > Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
> > Cc: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >   tests/qtest/e1000e-test.c | 8 ++++++--
> >   tests/qtest/igb-test.c    | 8 ++++++--
> >   2 files changed, 12 insertions(+), 4 deletions(-)
> > 
> > diff --git a/tests/qtest/e1000e-test.c b/tests/qtest/e1000e-test.c
> > index de9738fdb74..a69759da70e 100644
> > --- a/tests/qtest/e1000e-test.c
> > +++ b/tests/qtest/e1000e-test.c
> > @@ -64,8 +64,10 @@ static void e1000e_send_verify(QE1000E *d, int *test_sockets, QGuestAllocator *a
> >       /* Put descriptor to the ring */
> >       e1000e_tx_ring_push(d, &descr);
> >   
> > -    /* Wait for TX WB interrupt */
> > +    /* Wait for TX WB interrupt (this clears the MSIX PBA) */
>
> It doesn't clear the MSI-X PBA unless the next patch is applied. This 
> comment change should be moved to that patch.

Good catch. That was leftover from my improper PBA write patch.

> >       e1000e_wait_isr(d, E1000E_TX0_MSG_ID);
> > +    /* Read ICR which clears it ready for next interrupt, assert TXQ0 cause */
>
> I suggest the following to make this comment clearer:
> Read ICR to make it ready for next interrupt, assert TXQ0 cause

Sure.

Thanks,
Nick