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Commit 52a2a108 authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Tejun Heo
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sata_rcar: fix interrupt handling 



The driver's interrupt handling code is too picky in deciding whether it should
handle an interrupt or not which causes completely unneeded spurious interrupts.
Thus make sata_rcar_{ata|serr}_interrupt() *void*; add ATA status register read
to sata_rcar_ata_interrupt() to clear an unexpected ATA interrupt -- it doesn't
get cleared by writing to the SATAINTSTAT register in the interrupt mode we use.

Also, in sata_rcar_ata_interrupt() we should check SATAINTSTAT register only for
enabled interrupts and we should clear  only those interrupts  that we have read
as active first time around, because else we have  a  race and risk clearing  an
interrupt that  can  occur between read  and write of the  SATAINTSTAT  register
and never registering it...

Signed-off-by: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
parent fcce9a35

drivers/ata/sata_rcar.c

+11 −12
Original line number Diff line number Diff line
@@ -619,17 +619,16 @@ static struct ata_port_operations sata_rcar_port_ops = { 
	.bmdma_status		= sata_rcar_bmdma_status,

};



static int sata_rcar_serr_interrupt(struct ata_port *ap)

static void sata_rcar_serr_interrupt(struct ata_port *ap)

{

	struct sata_rcar_priv *priv = ap->host->private_data;

	struct ata_eh_info *ehi = &ap->link.eh_info;

	int freeze = 0;

	int handled = 0;

	u32 serror;



	serror = ioread32(priv->base + SCRSERR_REG);

	if (!serror)

		return 0;

		return;



	DPRINTK("SError @host_intr: 0x%x\n", serror);
@@ -642,7 +641,6 @@ static int sata_rcar_serr_interrupt(struct ata_port *ap) 
		ata_ehi_push_desc(ehi, "%s", "hotplug");



		freeze = serror & SERR_COMM_WAKE ? 0 : 1;

		handled = 1;

	}



	/* freeze or abort */
@@ -650,11 +648,9 @@ static int sata_rcar_serr_interrupt(struct ata_port *ap) 
		ata_port_freeze(ap);

	else

		ata_port_abort(ap);



	return handled;

}



static int sata_rcar_ata_interrupt(struct ata_port *ap)

static void sata_rcar_ata_interrupt(struct ata_port *ap)

{

	struct ata_queued_cmd *qc;

	int handled = 0;
@@ -663,7 +659,9 @@ static int sata_rcar_ata_interrupt(struct ata_port *ap) 
	if (qc)

		handled |= ata_bmdma_port_intr(ap, qc);



	return handled;

	/* be sure to clear ATA interrupt */

	if (!handled)

		sata_rcar_check_status(ap);

}



static irqreturn_t sata_rcar_interrupt(int irq, void *dev_instance)
@@ -678,20 +676,21 @@ static irqreturn_t sata_rcar_interrupt(int irq, void *dev_instance) 
	spin_lock_irqsave(&host->lock, flags);



	sataintstat = ioread32(priv->base + SATAINTSTAT_REG);

	sataintstat &= SATA_RCAR_INT_MASK;

	if (!sataintstat)

		goto done;

	/* ack */

	iowrite32(sataintstat & ~SATA_RCAR_INT_MASK,

		 priv->base + SATAINTSTAT_REG);

	iowrite32(~sataintstat & 0x7ff, priv->base + SATAINTSTAT_REG);



	ap = host->ports[0];



	if (sataintstat & SATAINTSTAT_ATA)

		handled |= sata_rcar_ata_interrupt(ap);

		sata_rcar_ata_interrupt(ap);



	if (sataintstat & SATAINTSTAT_SERR)

		handled |= sata_rcar_serr_interrupt(ap);

		sata_rcar_serr_interrupt(ap);



	handled = 1;

done:

	spin_unlock_irqrestore(&host->lock, flags);