libata-pmp-prep: implement ATA_HORKAGE_SKIP_PM
Some pseudo devices fail PM commands unnecessarily aborting system
suspend. Implement ATA_HORKAGE_SKIP_PM which makes libata skip PM
commands for these devices.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 8ca2cae..451f79c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -944,6 +944,13 @@
goto invalid_fld; /* LOEJ bit set not supported */
if (((cdb[4] >> 4) & 0xf) != 0)
goto invalid_fld; /* power conditions not supported */
+
+ if (qc->dev->horkage & ATA_HORKAGE_SKIP_PM) {
+ /* the device lacks PM support, finish without doing anything */
+ scmd->result = SAM_STAT_GOOD;
+ return 1;
+ }
+
if (cdb[4] & 0x1) {
tf->nsect = 1; /* 1 sector, lba=0 */