SATA: Blacklisting of systems that spin off disks during ACPI power off

Introduce new libata flags ATA_FLAG_NO_POWEROFF_SPINDOWN and
ATA_FLAG_NO_HIBERNATE_SPINDOWN that, if set, will prevent disks from
being spun off during system power off and hibernation, respectively
(to handle the hibernation case we need the new system state
SYSTEM_HIBERNATE_ENTER that can be checked against by libata, in
analogy with SYSTEM_POWER_OFF).

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/ata/libata-scsi.c

···
 #include <linux/libata.h>
 #include <linux/hdreg.h>
 #include <linux/uaccess.h>
+#include <linux/suspend.h>
 
 #include "libata.h"
 
···
 
 		tf->command = ATA_CMD_VERIFY;	/* READ VERIFY */
 	} else {
+		/* Some odd clown BIOSen issue spindown on power off (ACPI S4
+		 * or S5) causing some drives to spin up and down again.
+		 */
+		if ((qc->ap->flags & ATA_FLAG_NO_POWEROFF_SPINDOWN) &&
+		    system_state == SYSTEM_POWER_OFF)
+			goto skip;
+
+		if ((qc->ap->flags & ATA_FLAG_NO_HIBERNATE_SPINDOWN) &&
+		     system_entering_hibernation())
+			goto skip;
+
 		/* XXX: This is for backward compatibility, will be
 		 * removed.  Read Documentation/feature-removal-schedule.txt
 		 * for more info.
···
 				scmd->scsi_done = qc->scsidone;
 				qc->scsidone = ata_delayed_done;
 			}
-			scmd->result = SAM_STAT_GOOD;
-			return 1;
+			goto skip;
 		}
 
 		/* Issue ATA STANDBY IMMEDIATE command */
···
 
 	return 0;
 
-invalid_fld:
+ invalid_fld:
 	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
 	/* "Invalid field in cbd" */
+	return 1;
+ skip:
+	scmd->result = SAM_STAT_GOOD;
 	return 1;
 }
 

include/linux/libata.h

···
 	ATA_FLAG_PIO_POLLING	= (1 << 9), /* use polling PIO if LLD
 					     * doesn't handle PIO interrupts */
 	ATA_FLAG_NCQ		= (1 << 10), /* host supports NCQ */
+	ATA_FLAG_NO_POWEROFF_SPINDOWN = (1 << 11), /* don't spindown before poweroff */
+	ATA_FLAG_NO_HIBERNATE_SPINDOWN = (1 << 12), /* don't spindown before hibernation */
 	ATA_FLAG_DEBUGMSG	= (1 << 13),
 	ATA_FLAG_IGN_SIMPLEX	= (1 << 15), /* ignore SIMPLEX */
 	ATA_FLAG_NO_IORDY	= (1 << 16), /* controller lacks iordy */