From b887030aec0971a47ca97a18e93ff446bc7d049e Mon Sep 17 00:00:00 2001 From: Andrew Chew Date: Wed, 4 Jan 2006 19:13:04 -0800 Subject: [PATCH] [PATCH] sata_nv, spurious interrupts at system startup with MAXTOR 6H500F0 drive This patch works around a problem with spurious interrupts seen at boot time when a MAXTOR 6H500F0 drive is present. An ATA interrupt condition is mysteriously present at start of day. If we took too long in issuing the first command, the kernel would basically get tired of the spurious interrupts and turn the interrupt off. Issuing the first command essentially causes the interrupt condition to get acknowledged. I haven't seen this happen with any other drives. What I basically do is ack ATA status by reading it regardless of whether we're expecting to have to handle an interrupt. This clears the start-of-day anomalous interrupt condition, and keeps the kernel from disabling that interrupt due to too many spurious interrupts. Also, I fixed a bug where hotplug interrupts weren't getting acknowledged as handled in the ISR. This was not the cause of the spurious interrupts, but it's the right thing to do anyway. Signed-Off-By: Andrew Chew Signed-off-by: Jeff Garzik --- drivers/scsi/sata_nv.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/sata_nv.c b/drivers/scsi/sata_nv.c index c0cf52cb975a..bbbb55eeb73a 100644 --- a/drivers/scsi/sata_nv.c +++ b/drivers/scsi/sata_nv.c @@ -29,6 +29,12 @@ * NV-specific details such as register offsets, SATA phy location, * hotplug info, etc. * + * 0.10 + * - Fixed spurious interrupts issue seen with the Maxtor 6H500F0 500GB + * drive. Also made the check_hotplug() callbacks return whether there + * was a hotplug interrupt or not. This was not the source of the + * spurious interrupts, but is the right thing to do anyway. + * * 0.09 * - Fixed bug introduced by 0.08's MCP51 and MCP55 support. * @@ -124,10 +130,10 @@ static void nv_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val); static void nv_host_stop (struct ata_host_set *host_set); static void nv_enable_hotplug(struct ata_probe_ent *probe_ent); static void nv_disable_hotplug(struct ata_host_set *host_set); -static void nv_check_hotplug(struct ata_host_set *host_set); +static int nv_check_hotplug(struct ata_host_set *host_set); static void nv_enable_hotplug_ck804(struct ata_probe_ent *probe_ent); static void nv_disable_hotplug_ck804(struct ata_host_set *host_set); -static void nv_check_hotplug_ck804(struct ata_host_set *host_set); +static int nv_check_hotplug_ck804(struct ata_host_set *host_set); enum nv_host_type { @@ -176,7 +182,7 @@ struct nv_host_desc enum nv_host_type host_type; void (*enable_hotplug)(struct ata_probe_ent *probe_ent); void (*disable_hotplug)(struct ata_host_set *host_set); - void (*check_hotplug)(struct ata_host_set *host_set); + int (*check_hotplug)(struct ata_host_set *host_set); }; static struct nv_host_desc nv_device_tbl[] = { @@ -309,12 +315,16 @@ static irqreturn_t nv_interrupt (int irq, void *dev_instance, qc = ata_qc_from_tag(ap, ap->active_tag); if (qc && (!(qc->tf.ctl & ATA_NIEN))) handled += ata_host_intr(ap, qc); + else + // No request pending? Clear interrupt status + // anyway, in case there's one pending. + ap->ops->check_status(ap); } } if (host->host_desc->check_hotplug) - host->host_desc->check_hotplug(host_set); + handled += host->host_desc->check_hotplug(host_set); spin_unlock_irqrestore(&host_set->lock, flags); @@ -497,7 +507,7 @@ static void nv_disable_hotplug(struct ata_host_set *host_set) outb(intr_mask, host_set->ports[0]->ioaddr.scr_addr + NV_INT_ENABLE); } -static void nv_check_hotplug(struct ata_host_set *host_set) +static int nv_check_hotplug(struct ata_host_set *host_set) { u8 intr_status; @@ -522,7 +532,11 @@ static void nv_check_hotplug(struct ata_host_set *host_set) if (intr_status & NV_INT_STATUS_SDEV_REMOVED) printk(KERN_WARNING "nv_sata: " "Secondary device removed\n"); + + return 1; } + + return 0; } static void nv_enable_hotplug_ck804(struct ata_probe_ent *probe_ent) @@ -560,7 +574,7 @@ static void nv_disable_hotplug_ck804(struct ata_host_set *host_set) pci_write_config_byte(pdev, NV_MCP_SATA_CFG_20, regval); } -static void nv_check_hotplug_ck804(struct ata_host_set *host_set) +static int nv_check_hotplug_ck804(struct ata_host_set *host_set) { u8 intr_status; @@ -585,7 +599,11 @@ static void nv_check_hotplug_ck804(struct ata_host_set *host_set) if (intr_status & NV_INT_STATUS_SDEV_REMOVED) printk(KERN_WARNING "nv_sata: " "Secondary device removed\n"); + + return 1; } + + return 0; } static int __init nv_init(void) -- 2.30.2