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Commit c96f1732 authored by Alan Cox's avatar Alan Cox Committed by Jeff Garzik
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[libata] Improve timeout handling 



On a timeout call a device specific handler early in the recovery so that
we can complete and process successful commands which timed out due to IRQ
loss or the like rather more elegantly.

[Revised to exclude the timeout handling on a few devices that inherit from
 SFF but are not SFF enough to use the default timeout handler]

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 3d47aa8e

drivers/ata/libata-eh.c

+17 −2
Original line number Diff line number Diff line
@@ -547,7 +547,7 @@ void ata_scsi_error(struct Scsi_Host *host) 


	/* For new EH, all qcs are finished in one of three ways -

	 * normal completion, error completion, and SCSI timeout.

	 * Both cmpletions can race against SCSI timeout.  When normal

	 * Both completions can race against SCSI timeout.  When normal

	 * completion wins, the qc never reaches EH.  When error

	 * completion wins, the qc has ATA_QCFLAG_FAILED set.

	 *
@@ -563,6 +563,18 @@ void ata_scsi_error(struct Scsi_Host *host) 


		spin_lock_irqsave(ap->lock, flags);

		

		/* This must occur under the ap->lock as we don't want

		   a polled recovery to race the real interrupt handler

		   

		   The lost_interrupt handler checks for any completed but

		   non-notified command and completes much like an IRQ handler.

		   

		   We then fall into the error recovery code which will treat

		   this as if normal completion won the race */



		if (ap->ops->lost_interrupt)

			ap->ops->lost_interrupt(ap);

			

		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {

			struct ata_queued_cmd *qc;
@@ -607,6 +619,9 @@ void ata_scsi_error(struct Scsi_Host *host) 
	} else

		spin_unlock_wait(ap->lock);

		

	/* If we timed raced normal completion and there is nothing to

	   recover nr_timedout == 0 why exactly are we doing error recovery ? */



 repeat:

	/* invoke error handler */

	if (ap->ops->error_handler) {

drivers/ata/libata-sff.c

+45 −1
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ const struct ata_port_operations ata_sff_port_ops = { 
	.sff_irq_on		= ata_sff_irq_on,

	.sff_irq_clear		= ata_sff_irq_clear,



	.lost_interrupt		= ata_sff_lost_interrupt,



	.port_start		= ata_sff_port_start,

};

EXPORT_SYMBOL_GPL(ata_sff_port_ops);
@@ -1647,7 +1649,7 @@ EXPORT_SYMBOL_GPL(ata_sff_qc_fill_rtf); 
 *	RETURNS:

 *	One if interrupt was handled, zero if not (shared irq).

 */

inline unsigned int ata_sff_host_intr(struct ata_port *ap,

unsigned int ata_sff_host_intr(struct ata_port *ap,

				      struct ata_queued_cmd *qc)

{

	struct ata_eh_info *ehi = &ap->link.eh_info;
@@ -1775,6 +1777,48 @@ irqreturn_t ata_sff_interrupt(int irq, void *dev_instance) 
}

EXPORT_SYMBOL_GPL(ata_sff_interrupt);



/**

 *	ata_sff_lost_interrupt	-	Check for an apparent lost interrupt

 *	@ap: port that appears to have timed out

 *

 *	Called from the libata error handlers when the core code suspects

 *	an interrupt has been lost. If it has complete anything we can and

 *	then return. Interface must support altstatus for this faster

 *	recovery to occur.

 *

 *	Locking:

 *	Caller holds host lock

 */



void ata_sff_lost_interrupt(struct ata_port *ap)

{

	u8 status;

	struct ata_queued_cmd *qc;



	/* Only one outstanding command per SFF channel */

	qc = ata_qc_from_tag(ap, ap->link.active_tag);

	/* Check we have a live one.. */

	if (qc == NULL ||  !(qc->flags & ATA_QCFLAG_ACTIVE))

		return;

	/* We cannot lose an interrupt on a polled command */

	if (qc->tf.flags & ATA_TFLAG_POLLING)

		return;

	/* See if the controller thinks it is still busy - if so the command

	   isn't a lost IRQ but is still in progress */

	status = ata_sff_altstatus(ap);

	if (status & ATA_BUSY)

		return;



	/* There was a command running, we are no longer busy and we have

	   no interrupt. */

	ata_port_printk(ap, KERN_WARNING, "lost interrupt (Status 0x%x)\n",

								status);

	/* Run the host interrupt logic as if the interrupt had not been

	   lost */

	ata_sff_host_intr(ap, qc);

}

EXPORT_SYMBOL_GPL(ata_sff_lost_interrupt);



/**

 *	ata_sff_freeze - Freeze SFF controller port

 *	@ap: port to freeze

drivers/ata/pata_isapnp.c

+10 −2
Original line number Diff line number Diff line
@@ -17,7 +17,7 @@ 
#include <linux/libata.h>



#define DRV_NAME "pata_isapnp"

#define DRV_VERSION "0.2.2"

#define DRV_VERSION "0.2.5"



static struct scsi_host_template isapnp_sht = {

	ATA_PIO_SHT(DRV_NAME),
@@ -28,6 +28,13 @@ static struct ata_port_operations isapnp_port_ops = { 
	.cable_detect	= ata_cable_40wire,

};



static struct ata_port_operations isapnp_noalt_port_ops = {

	.inherits	= &ata_sff_port_ops,

	.cable_detect	= ata_cable_40wire,

	/* No altstatus so we don't want to use the lost interrupt poll */

	.lost_interrupt = ATA_OP_NULL,

};



/**

 *	isapnp_init_one		-	attach an isapnp interface

 *	@idev: PnP device
@@ -65,7 +72,7 @@ static int isapnp_init_one(struct pnp_dev *idev, const struct pnp_device_id *dev 


	ap = host->ports[0];



	ap->ops = &isapnp_port_ops;

	ap->ops = &isapnp_noalt_port_ops;

	ap->pio_mask = ATA_PIO0;

	ap->flags |= ATA_FLAG_SLAVE_POSS;
@@ -76,6 +83,7 @@ static int isapnp_init_one(struct pnp_dev *idev, const struct pnp_device_id *dev 
					   pnp_port_start(idev, 1), 1);

		ap->ioaddr.altstatus_addr = ctl_addr;

		ap->ioaddr.ctl_addr = ctl_addr;

		ap->ops = &isapnp_port_ops;

	}



	ata_sff_std_ports(&ap->ioaddr);

drivers/ata/pdc_adma.c

+2 −0
Original line number Diff line number Diff line
@@ -148,6 +148,8 @@ static struct scsi_host_template adma_ata_sht = { 
static struct ata_port_operations adma_ata_ops = {

	.inherits		= &ata_sff_port_ops,



	.lost_interrupt		= ATA_OP_NULL,



	.check_atapi_dma	= adma_check_atapi_dma,

	.qc_prep		= adma_qc_prep,

	.qc_issue		= adma_qc_issue,

drivers/ata/sata_mv.c

+2 −0
Original line number Diff line number Diff line
@@ -646,6 +646,8 @@ static struct scsi_host_template mv6_sht = { 
static struct ata_port_operations mv5_ops = {

	.inherits		= &ata_sff_port_ops,



	.lost_interrupt		= ATA_OP_NULL,



	.qc_defer		= mv_qc_defer,

	.qc_prep		= mv_qc_prep,

	.qc_issue		= mv_qc_issue,