libertas: fix GSPI card event handling

[Dan Williams]

On Tue, 2009-05-19 at 17:20 -0700, andrey at cozybit.com 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 at cozybit.com>

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... 

Dan

> 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);
> 
>