libata-pmp-prep: implement sata_async_notification()
AN serves multiple purposes. For ATAPI, it's used for media change
notification. For PMP, for downstream PHY status change notification.
Implement sata_async_notification() which demultiplexes AN.
To avoid unnecessary port events, ATAPI AN is not enabled if PMP is
attached but SNTF is not available.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 376dbd8..8b08e7b 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2016,6 +2016,7 @@
else if (dev->class == ATA_DEV_ATAPI) {
const char *cdb_intr_string = "";
const char *atapi_an_string = "";
+ u32 sntf;
rc = atapi_cdb_len(id);
if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
@@ -2027,11 +2028,14 @@
}
dev->cdb_len = (unsigned int) rc;
- /*
- * check to see if this ATAPI device supports
- * Asynchronous Notification
+ /* Enable ATAPI AN if both the host and device have
+ * the support. If PMP is attached, SNTF is required
+ * to enable ATAPI AN to discern between PHY status
+ * changed notifications and ATAPI ANs.
*/
- if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id)) {
+ if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
+ (!ap->nr_pmp_links ||
+ sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
unsigned int err_mask;
/* issue SET feature command to turn this on */
@@ -7248,6 +7252,7 @@
EXPORT_SYMBOL_GPL(ata_link_abort);
EXPORT_SYMBOL_GPL(ata_port_abort);
EXPORT_SYMBOL_GPL(ata_port_freeze);
+EXPORT_SYMBOL_GPL(sata_async_notification);
EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
EXPORT_SYMBOL_GPL(ata_eh_qc_complete);