From f4d6d00466ef4879e4289f18c2f59210a06a7ada Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 May 2007 11:50:15 +0200 Subject: [PATCH] libata: ignore EH scheduling during initialization libata enables SCSI host during ATA host activation which happens after IRQ handler is registered and IRQ is enabled. All ATA ports are in frozen state when IRQ is enabled but frozen ports may raise limited number of IRQs after being frozen - IOW, ->freeze() is not responsible for clearing pending IRQs. During normal operation, the IRQ handler is responsible for clearing spurious IRQs on frozen ports and it usually doesn't require any extra code. Unfortunately, during host initialization, the IRQ handler can end up scheduling EH for a port whose SCSI host isn't initialized yet. This results in OOPS in the SCSI midlayer. This is relatively short window and scheduling EH for probing is the first thing libata does after initialization, so ignoring EH scheduling until initialization is complete solves the problem nicely. This problem was spotted by Berck E. Nash in the following thread. http://thread.gmane.org/gmane.linux.kernel/519412 Signed-off-by: Tejun Heo Cc: Berck E. Nash Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 2 ++ drivers/ata/libata-eh.c | 3 +++ include/linux/libata.h | 1 + 3 files changed, 6 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 9cff5c506573..6ac4f32ddcc2 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5964,6 +5964,7 @@ struct ata_port *ata_port_alloc(struct ata_host *host) if (!ap) return NULL; + ap->pflags |= ATA_PFLAG_INITIALIZING; ap->lock = &host->lock; ap->flags = ATA_FLAG_DISABLED; ap->print_id = -1; @@ -6332,6 +6333,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht) ehi->action |= ATA_EH_SOFTRESET; ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET; + ap->pflags &= ~ATA_PFLAG_INITIALIZING; ap->pflags |= ATA_PFLAG_LOADING; ata_port_schedule_eh(ap); diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 412d6049afa3..ee9bb534153a 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -551,6 +551,9 @@ void ata_port_schedule_eh(struct ata_port *ap) { WARN_ON(!ap->ops->error_handler); + if (ap->pflags & ATA_PFLAG_INITIALIZING) + return; + ap->pflags |= ATA_PFLAG_EH_PENDING; scsi_schedule_eh(ap->scsi_host); diff --git a/include/linux/libata.h b/include/linux/libata.h index 95b74ba7dbf4..90abcdc3d4ef 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -190,6 +190,7 @@ enum { ATA_PFLAG_LOADING = (1 << 4), /* boot/loading probe */ ATA_PFLAG_UNLOADING = (1 << 5), /* module is unloading */ ATA_PFLAG_SCSI_HOTPLUG = (1 << 6), /* SCSI hotplug scheduled */ + ATA_PFLAG_INITIALIZING = (1 << 7), /* being initialized, don't touch */ ATA_PFLAG_FLUSH_PORT_TASK = (1 << 16), /* flush port task */ ATA_PFLAG_SUSPENDED = (1 << 17), /* port is suspended (power) */