On Wed, 2009-05-20 at 15:28 -0700, Andrey Yurovsky wrote: > On Wed, May 20, 2009 at 3:18 PM, Dan Williams <dcbw@xxxxxxxxxx> wrote: > > On Tue, 2009-05-19 at 17:20 -0700, andrey@xxxxxxxxxxx wrote: > >> The GPSI interface driver does not re-enable the Card Event Interrupt, which > >> causes problems after a card event (for example: link-loss) comes in. This > >> can lead, for example, to the card failing to re-associate. This patch > >> ensures that we re-enable the Card Event Interrupt when we handle card events. > >> > >> Signed-off-by: Andrey Yurovsky <andrey@xxxxxxxxxxx> > > > > Where does that bit ever get disabled? Is that done by the firmware > > after it sends the interrupt? I don't think I quite understand what's > > going on here... > > That's correct. The firmware and host communicate by setting or > clearing bits and forcing an interrupt. The event mechanism is, > basically: > 1) firmware sets that bit and triggers an IRQ > 2) host handles the IRQ (noticing that it's an Event and reading the > Event Cause) > 3) host clears the bit > 4) host triggers an interrupt (on the card) so that the card notices > the change (ie: that the bit was cleared) Ah, step 4 was what I wasn't yet thinking of. Sounds fine. Acked-by: Dan Williams <dcbw@xxxxxxxxxx> > Steps 3 an 4 were missing in if_spi.c, which caused problems if, for > example, you associate to an AP and then cut the AP's power. In this > case the card will never re-associate subsequently because the Card > Event bit never gets cleared. > > >> diff --git a/drivers/net/wireless/libertas/if_spi.c b/drivers/net/wireless/libertas/if_spi.c > >> index dccd01f..5fa55fe 100644 > >> --- a/drivers/net/wireless/libertas/if_spi.c > >> +++ b/drivers/net/wireless/libertas/if_spi.c > >> @@ -814,6 +814,13 @@ static void if_spi_e2h(struct if_spi_card *card) > >> if (err) > >> goto out; > >> > >> + /* re-enable the card event interrupt */ > >> + spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, > >> + ~IF_SPI_HICU_CARD_EVENT); > >> + > >> + /* generate a card interrupt */ > >> + spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG, IF_SPI_CIC_HOST_EVENT); > >> + > >> spin_lock_irqsave(&priv->driver_lock, flags); > >> lbs_queue_event(priv, cause & 0xff); > >> spin_unlock_irqrestore(&priv->driver_lock, flags); > >> > >> > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
