libata: ignore EH scheduling during initialization (f4d6d004) · Commits · 戴 / test

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 <htejun@gmail.com> Cc: Berck E. Nash <flyboy@gmail.com> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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);

drivers/ata/libata-eh.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);

include/linux/libata.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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) */

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