Commit 43d01c56 authored by Holger Schurig's avatar Holger Schurig Committed by John W. Linville
Browse files

libertas: fix compact flash interrupt handling 



The old code misbehaved because it polled card status and always called the
"tx over" code-path.

This also fixes a hard lockup by not allowing and card interrupts while
transferring a TX frame or a command into the card.

Signed-off-by: default avatarHolger Schurig <hs4233@mail.mn-solutions.de>
Acked-by: default avatarDan Williams <dcbw@redhat.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 85319f93

drivers/net/wireless/libertas/if_cs.c

+29 −32
Original line number Diff line number Diff line
@@ -215,9 +215,21 @@ static int if_cs_poll_while_fw_download(struct if_cs_card *card, uint addr, u8 r 




/********************************************************************/

/* I/O                                                              */

/* I/O and interrupt handling                                       */

/********************************************************************/



static inline void if_cs_enable_ints(struct if_cs_card *card)

{

	lbs_deb_enter(LBS_DEB_CS);

	if_cs_write16(card, IF_CS_H_INT_MASK, 0);

}



static inline void if_cs_disable_ints(struct if_cs_card *card)

{

	lbs_deb_enter(LBS_DEB_CS);

	if_cs_write16(card, IF_CS_H_INT_MASK, IF_CS_H_IM_MASK);

}



/*

 * Called from if_cs_host_to_card to send a command to the hardware

 */
@@ -228,6 +240,7 @@ static int if_cs_send_cmd(struct lbs_private *priv, u8 *buf, u16 nb) 
	int loops = 0;



	lbs_deb_enter(LBS_DEB_CS);

	if_cs_disable_ints(card);



	/* Is hardware ready? */

	while (1) {
@@ -258,19 +271,24 @@ static int if_cs_send_cmd(struct lbs_private *priv, u8 *buf, u16 nb) 
	ret = 0;



done:

	if_cs_enable_ints(card);

	lbs_deb_leave_args(LBS_DEB_CS, "ret %d", ret);

	return ret;

}





/*

 * Called from if_cs_host_to_card to send a data to the hardware

 */

static void if_cs_send_data(struct lbs_private *priv, u8 *buf, u16 nb)

{

	struct if_cs_card *card = (struct if_cs_card *)priv->card;

	u16 status;



	lbs_deb_enter(LBS_DEB_CS);

	if_cs_disable_ints(card);



	status = if_cs_read16(card, IF_CS_C_STATUS);

	BUG_ON((status & IF_CS_C_S_TX_DNLD_RDY) == 0);



	if_cs_write16(card, IF_CS_H_WRITE_LEN, nb);
@@ -281,11 +299,11 @@ static void if_cs_send_data(struct lbs_private *priv, u8 *buf, u16 nb) 


	if_cs_write16(card, IF_CS_H_STATUS, IF_CS_H_STATUS_TX_OVER);

	if_cs_write16(card, IF_CS_H_INT_CAUSE, IF_CS_H_STATUS_TX_OVER);

	if_cs_enable_ints(card);



	lbs_deb_leave(LBS_DEB_CS);

}





/*

 * Get the command result out of the card.

 */
@@ -330,7 +348,6 @@ out: 
	return ret;

}





static struct sk_buff *if_cs_receive_data(struct lbs_private *priv)

{

	struct sk_buff *skb = NULL;
@@ -367,25 +384,6 @@ out: 
	return skb;

}







/********************************************************************/

/* Interrupts                                                       */

/********************************************************************/



static inline void if_cs_enable_ints(struct if_cs_card *card)

{

	lbs_deb_enter(LBS_DEB_CS);

	if_cs_write16(card, IF_CS_H_INT_MASK, 0);

}



static inline void if_cs_disable_ints(struct if_cs_card *card)

{

	lbs_deb_enter(LBS_DEB_CS);

	if_cs_write16(card, IF_CS_H_INT_MASK, IF_CS_H_IM_MASK);

}





static irqreturn_t if_cs_interrupt(int irq, void *data)

{

	struct if_cs_card *card = data;
@@ -394,10 +392,8 @@ static irqreturn_t if_cs_interrupt(int irq, void *data) 


	lbs_deb_enter(LBS_DEB_CS);



	/* Ask card interrupt cause register if there is something for us */

	cause = if_cs_read16(card, IF_CS_C_INT_CAUSE);

	if_cs_write16(card, IF_CS_C_INT_CAUSE, cause & IF_CS_C_IC_MASK);



	lbs_deb_cs("cause 0x%04x\n", cause);

	if (cause == 0) {

		/* Not for us */

		return IRQ_NONE;
@@ -409,9 +405,9 @@ static irqreturn_t if_cs_interrupt(int irq, void *data) 
		return IRQ_HANDLED;

	}



	/* TODO: I'm not sure what the best ordering is */



	cause = if_cs_read16(card, IF_CS_C_STATUS) & IF_CS_C_S_MASK;

	/* Clear interrupt cause */

	if_cs_write16(card, IF_CS_C_INT_CAUSE, cause & IF_CS_C_IC_MASK);

	lbs_deb_cs("cause 0x%04x\n", cause);



	if (cause & IF_CS_C_S_RX_UPLD_RDY) {

		struct sk_buff *skb;
@@ -422,7 +418,7 @@ static irqreturn_t if_cs_interrupt(int irq, void *data) 
	}



	if (cause & IF_CS_H_IC_TX_OVER) {

		lbs_deb_cs("tx over\n");

		lbs_deb_cs("tx done\n");

		lbs_host_to_card_done(priv);

	}
@@ -430,7 +426,7 @@ static irqreturn_t if_cs_interrupt(int irq, void *data) 
		unsigned long flags;

		u8 i;



		lbs_deb_cs("cmd upload ready\n");

		lbs_deb_cs("cmd resp\n");

		spin_lock_irqsave(&priv->driver_lock, flags);

		i = (priv->resp_idx == 0) ? 1 : 0;

		spin_unlock_irqrestore(&priv->driver_lock, flags);
@@ -449,10 +445,11 @@ static irqreturn_t if_cs_interrupt(int irq, void *data) 
			& IF_CS_C_S_STATUS_MASK;

		if_cs_write16(priv->card, IF_CS_H_INT_CAUSE,

			IF_CS_H_IC_HOST_EVENT);

		lbs_deb_cs("eventcause 0x%04x\n", event);

		lbs_deb_cs("host event 0x%04x\n", event);

		lbs_queue_event(priv, event >> 8 & 0xff);

	}



	lbs_deb_leave(LBS_DEB_CS);

	return IRQ_HANDLED;

}

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