ahci: EM message type auto detect

Detect enclosure management message type automatically at driver
initialization, instead of using module parameter "ahci_em_messages".

Signed-off-by: Harry Zhang <harry.zhang@amd.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 20 insertions, 18 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 34fc57d0a9b8..817bcd023cc0 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -184,7 +184,7 @@ EXPORT_SYMBOL_GPL(ahci_em_messages);
 module_param(ahci_em_messages, int, 0444);
 /* add other LED protocol types when they become supported */
 MODULE_PARM_DESC(ahci_em_messages,
-        "Set AHCI Enclosure Management Message type (0 = disabled, 1 = LED");
+        "AHCI Enclosure Management Message control (0 = off, 1 = on)");
 
 static void ahci_enable_ahci(void __iomem *mmio)
 {
@@ -931,27 +931,29 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
                 return -EBUSY;
         }
 
-        /*
-         * create message header - this is all zero except for
-         * the message size, which is 4 bytes.
-         */
-        message[0] |= (4 << 8);
+        if (hpriv->em_msg_type & EM_MSG_TYPE_LED) {
+                /*
+                 * create message header - this is all zero except for
+                 * the message size, which is 4 bytes.
+                 */
+                message[0] |= (4 << 8);
 
-        /* ignore 0:4 of byte zero, fill in port info yourself */
-        message[1] = ((state & ~EM_MSG_LED_HBA_PORT) | ap->port_no);
+                /* ignore 0:4 of byte zero, fill in port info yourself */
+                message[1] = ((state & ~EM_MSG_LED_HBA_PORT) | ap->port_no);
 
-        /* write message to EM_LOC */
-        writel(message[0], mmio + hpriv->em_loc);
-        writel(message[1], mmio + hpriv->em_loc+4);
+                /* write message to EM_LOC */
+                writel(message[0], mmio + hpriv->em_loc);
+                writel(message[1], mmio + hpriv->em_loc+4);
+
+                /*
+                 * tell hardware to transmit the message
+                 */
+                writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+        }
 
         /* save off new led state for port/slot */
         emp->led_state = state;
 
-        /*
-         * tell hardware to transmit the message
-         */
-        writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
-
         spin_unlock_irqrestore(ap->lock, flags);
         return size;
 }
@@ -2094,10 +2096,10 @@ void ahci_set_em_messages(struct ahci_host_priv *hpriv,
 
         messages = (em_ctl & EM_CTRL_MSG_TYPE) >> 16;
 
-        /* we only support LED message type right now */
-        if ((messages & 0x01) && (ahci_em_messages == 1)) {
+        if (messages) {
                 /* store em_loc */
                 hpriv->em_loc = ((em_loc >> 16) * 4);
+                hpriv->em_msg_type = messages;
                 pi->flags |= ATA_FLAG_EM;
                 if (!(em_ctl & EM_CTL_ALHD))
                         pi->flags |= ATA_FLAG_SW_ACTIVITY;