From: Alan Cox Date: Tue, 24 Mar 2009 10:23:46 +0000 (+0000) Subject: [libata] Improve timeout handling X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=c96f1732e25362d10ee7bcac1df8412a2e6b7d23;p=linux-2.6-omap-h63xx.git [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 --- diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index ea890911d4f..01831312c36 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -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. * @@ -562,7 +562,19 @@ void ata_scsi_error(struct Scsi_Host *host) int nr_timedout = 0; 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; @@ -606,6 +618,9 @@ void ata_scsi_error(struct Scsi_Host *host) ap->eh_tries = ATA_EH_MAX_TRIES; } 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 */ diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c index 9a10cb055ac..8332e97a9de 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 diff --git a/drivers/ata/pata_isapnp.c b/drivers/ata/pata_isapnp.c index afa8f704271..4bceb8803a1 100644 --- a/drivers/ata/pata_isapnp.c +++ b/drivers/ata/pata_isapnp.c @@ -17,7 +17,7 @@ #include #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); diff --git a/drivers/ata/pdc_adma.c b/drivers/ata/pdc_adma.c index c509c206a45..39588178d02 100644 --- a/drivers/ata/pdc_adma.c +++ b/drivers/ata/pdc_adma.c @@ -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, diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c index 8a751054c8a..a377226b81c 100644 --- a/drivers/ata/sata_mv.c +++ b/drivers/ata/sata_mv.c @@ -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, diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c index 2f523f8c27f..6cda12ba812 100644 --- a/drivers/ata/sata_nv.c +++ b/drivers/ata/sata_nv.c @@ -408,6 +408,7 @@ static struct scsi_host_template nv_swncq_sht = { static struct ata_port_operations nv_common_ops = { .inherits = &ata_bmdma_port_ops, + .lost_interrupt = ATA_OP_NULL, .scr_read = nv_scr_read, .scr_write = nv_scr_write, }; diff --git a/drivers/ata/sata_promise.c b/drivers/ata/sata_promise.c index 3ad2b886363..b1fd7d62071 100644 --- a/drivers/ata/sata_promise.c +++ b/drivers/ata/sata_promise.c @@ -176,7 +176,9 @@ static const struct ata_port_operations pdc_common_ops = { .check_atapi_dma = pdc_check_atapi_dma, .qc_prep = pdc_qc_prep, .qc_issue = pdc_qc_issue, + .sff_irq_clear = pdc_irq_clear, + .lost_interrupt = ATA_OP_NULL, .post_internal_cmd = pdc_post_internal_cmd, .error_handler = pdc_error_handler, diff --git a/drivers/ata/sata_qstor.c b/drivers/ata/sata_qstor.c index 7112d89fd9f..c3936d35cda 100644 --- a/drivers/ata/sata_qstor.c +++ b/drivers/ata/sata_qstor.c @@ -147,6 +147,7 @@ static struct ata_port_operations qs_ata_ops = { .softreset = ATA_OP_NULL, .error_handler = qs_error_handler, .post_internal_cmd = ATA_OP_NULL, + .lost_interrupt = ATA_OP_NULL, .scr_read = qs_scr_read, .scr_write = qs_scr_write, diff --git a/drivers/ata/sata_vsc.c b/drivers/ata/sata_vsc.c index ef211f333d7..ed70bd28fa2 100644 --- a/drivers/ata/sata_vsc.c +++ b/drivers/ata/sata_vsc.c @@ -308,6 +308,9 @@ static struct scsi_host_template vsc_sata_sht = { static struct ata_port_operations vsc_sata_ops = { .inherits = &ata_bmdma_port_ops, + /* The IRQ handling is not quite standard SFF behaviour so we + cannot use the default lost interrupt handler */ + .lost_interrupt = ATA_OP_NULL, .sff_tf_load = vsc_sata_tf_load, .sff_tf_read = vsc_sata_tf_read, .freeze = vsc_freeze, diff --git a/include/linux/libata.h b/include/linux/libata.h index 3a07a32dfc2..76262d83656 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -795,6 +795,7 @@ struct ata_port_operations { ata_reset_fn_t pmp_hardreset; ata_postreset_fn_t pmp_postreset; void (*error_handler)(struct ata_port *ap); + void (*lost_interrupt)(struct ata_port *ap); void (*post_internal_cmd)(struct ata_queued_cmd *qc); /* @@ -1577,6 +1578,7 @@ extern bool ata_sff_qc_fill_rtf(struct ata_queued_cmd *qc); extern unsigned int ata_sff_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc); extern irqreturn_t ata_sff_interrupt(int irq, void *dev_instance); +extern void ata_sff_lost_interrupt(struct ata_port *ap); extern void ata_sff_freeze(struct ata_port *ap); extern void ata_sff_thaw(struct ata_port *ap); extern int ata_sff_prereset(struct ata_link *link, unsigned long deadline);