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libertas: fix compact flash interrupt handling
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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: Holger Schurig <hs4233@mail.mn-solutions.de>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Holger Schurig authored and John W. Linville committed Jun 3, 2008
1 parent 85319f9 commit 43d01c5
Showing 1 changed file with 29 additions and 32 deletions.
61 changes: 29 additions & 32 deletions drivers/net/wireless/libertas/if_cs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
*/
Expand All @@ -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) {
Expand Down Expand Up @@ -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);

Expand All @@ -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.
*/
Expand Down Expand Up @@ -330,7 +348,6 @@ static int if_cs_receive_cmdres(struct lbs_private *priv, u8 *data, u32 *len)
return ret;
}


static struct sk_buff *if_cs_receive_data(struct lbs_private *priv)
{
struct sk_buff *skb = NULL;
Expand Down Expand Up @@ -367,25 +384,6 @@ static struct sk_buff *if_cs_receive_data(struct lbs_private *priv)
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;
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -422,15 +418,15 @@ 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);
}

if (cause & IF_CS_C_S_CMD_UPLD_RDY) {
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);
Expand All @@ -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;
}

Expand Down

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