patch for Attansic L2 FastEthernet

[Pyun YongHyeon]

On Mon, Jul 14, 2008 at 10:30:36PM +0800, mirnshi at gmail.com wrote:
 > Recently, I got an eeepc 701. And I installed FreeBSD 7.0 on it . The url
 > http://wiki.freebsd.org/AsusEee gives me a big hand. But, the driver of lan
 > did not work. The problem is that the driver can be loaded by kldload, but
 > the interrupt storm caused the system to stop responding when I use ifconfig
 > to mark the nic 'up'.  BTW, I used 10MB hub.

Sound like interrupts are enabled in taskqueue handler.

 > 
 > The driver uses taskqueue_enqueue. 'ae_intr' reads nic register, but
 > 'ae_int_task' reads it again. So I merge them into the new 'ae_intr'.
 > I test 'ping' and 'ftp', it works well.
 > 

You can't hold a mutex in fast interrupt handler.
Since there is no documentation for L2 controller I'm not sure but
ae_int_task() seems to have a code that reenables interrupts which
was already disabled in ae_intr(). How about nuking AE_ISR_DISABLE
in ae_int_task()?

From:
	/* Clear interrupts and disable them. */
	AE_WRITE_4(sc, AE_ISR_REG, val | AE_ISR_DISABLE);

To:
	/* Clear interrupts. */
	AE_WRITE_4(sc, AE_ISR_REG, val);

CCed to Stanislav Sedov, the author of driver.

 > Please refer to the patch for details.
 > 
 > --- if_ae.c    2008-06-27 20:19:43.000000000 +0800
 > +++ /sys/dev/if_ae/if_ae.c    2008-07-14 21:54:06.000000000 +0800
 > @@ -1450,20 +1450,56 @@
 >  {
 >      ae_softc_t *sc;
 >      uint32_t val;
 > +    struct ifnet *ifp;
 > +    struct mii_data *mii;
 > 
 >      sc = (ae_softc_t *)arg;
 > +    AE_LOCK(sc);
 >      KASSERT(sc != NULL, ("[ae, %d]: sc is null", __LINE__));
 > 
 >      val = AE_READ_4(sc, AE_ISR_REG);
 > -    if (val == 0 || (val & AE_IMR_DEFAULT) == 0)
 > +    if (val == 0 || (val & AE_IMR_DEFAULT) == 0) {
 > +        AE_UNLOCK(sc);
 >          return FILTER_STRAY;
 > +    }
 > 
 > -    /* Disable interrupts. */
 > -    AE_WRITE_4(sc, AE_ISR_REG, AE_ISR_DISABLE);
 > +    /* Clear interrupts and disable them. */
 > +    AE_WRITE_4(sc, AE_ISR_REG, val | AE_ISR_DISABLE);
 > 
 > -    /* Schedule interrupt processing. */
 > -    taskqueue_enqueue(sc->tq, &sc->int_task);
 > +    ifp = sc->ifp;
 > 
 > +    if ((val & AE_ISR_PHY) != 0) {
 > +        /*
 > +         * Clear PHY interrupt. Not sure if it needed. From Linux.
 > +         */
 > +        ae_miibus_readreg(sc->miibus, 1, 19);
 > +    }
 > +
 > +#ifdef AE_DEBUG
 > +    if_printf(ifp, "Interrupt received: 0x%08x\n", val);
 > +#endif
 > +
 > +    if ((val & (AE_ISR_PHY | AE_ISR_MANUAL)) != 0) {
 > +        mii = device_get_softc(sc->miibus);
 > +        mii_mediachg(mii);
 > +    }
 > +
 > +    if ((val & (AE_ISR_DMAR_TIMEOUT | AE_ISR_DMAW_TIMEOUT |
 > +        AE_ISR_PHY_LINKDOWN)) != 0) {
 > +        ae_init_locked(sc);
 > +    }
 > +    if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0) {
 > +        if ((val & AE_ISR_TX_EVENT) != 0)
 > +            ae_tx_intr(sc);
 > +
 > +        if ((val & AE_ISR_RX_EVENT) != 0)
 > +            ae_rx_intr(sc);
 > +    }
 > +
 > +    /* Re-enable interrupts. */
 > +    AE_WRITE_4(sc, AE_ISR_REG, 0);
 > +
 > +    AE_UNLOCK(sc);
 >      return (FILTER_HANDLED);
 >  }

-- 
Regards,
Pyun YongHyeon