From c96f1732e25362d10ee7bcac1df8412a2e6b7d23 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 24 Mar 2009 10:23:46 +0000 Subject: [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: Alan Cox Signed-off-by: Jeff Garzik --- drivers/ata/libata-sff.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) (limited to 'drivers/ata/libata-sff.c') diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c index 9a10cb055ac2..8332e97a9de3 100644 --- a/drivers/ata/libata-sff.c +++ b/drivers/ata/libata-sff.c @@ -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 -- cgit v1.2.3