libahci: Allow drivers to override stop_engine

Marvell armada37xx, armada7k and armada8k share the same
AHCI sata controller IP, and currently there is an issue
(Errata Ref#226)that the SATA can not be detected via SATA
Port-MultiPlayer(PMP). After debugging, the reason is
found that the value of Port-x FIS-based Switching Control
(PxFBS@0x40) became wrong.
According to design, the bits[11:8, 0] of register PxFBS
are cleared when Port Command and Status (0x18) bit[0]
changes its value from 1 to 0, i.e. falling edge of Port
Command and Status bit[0] sends PULSE that resets PxFBS
bits[11:8; 0].
So it needs save the port PxFBS register before PxCMD
ST write and restore the port PxFBS register afterwards
in ahci_stop_engine().

This commit allows drivers to override ahci_stop_engine
behavior for use by the Marvell AHCI driver(and potentially
other drivers in the future).

Signed-off-by: Evan Wang <xswang@marvell.com>
Cc: Ofer Heifetz <oferh@marvell.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 7adcf3caabd0..e5d90977caec 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -560,6 +560,9 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
         if (!hpriv->start_engine)
                 hpriv->start_engine = ahci_start_engine;
 
+        if (!hpriv->stop_engine)
+                hpriv->stop_engine = ahci_stop_engine;
+
         if (!hpriv->irq_handler)
                 hpriv->irq_handler = ahci_single_level_irq_intr;
 }
@@ -897,9 +900,10 @@ static void ahci_start_port(struct ata_port *ap)
 static int ahci_deinit_port(struct ata_port *ap, const char **emsg)
 {
         int rc;
+        struct ahci_host_priv *hpriv = ap->host->private_data;
 
         /* disable DMA */
-        rc = ahci_stop_engine(ap);
+        rc = hpriv->stop_engine(ap);
         if (rc) {
                 *emsg = "failed to stop engine";
                 return rc;
@@ -1310,7 +1314,7 @@ int ahci_kick_engine(struct ata_port *ap)
         int busy, rc;
 
         /* stop engine */
-        rc = ahci_stop_engine(ap);
+        rc = hpriv->stop_engine(ap);
         if (rc)
                 goto out_restart;
 
@@ -1549,7 +1553,7 @@ int ahci_do_hardreset(struct ata_link *link, unsigned int *class,
 
         DPRINTK("ENTER\n");
 
-        ahci_stop_engine(ap);
+        hpriv->stop_engine(ap);
 
         /* clear D2H reception area to properly wait for D2H FIS */
         ata_tf_init(link->device, &tf);
@@ -2075,14 +2079,14 @@ void ahci_error_handler(struct ata_port *ap)
 
         if (!(ap->pflags & ATA_PFLAG_FROZEN)) {
                 /* restart engine */
-                ahci_stop_engine(ap);
+                hpriv->stop_engine(ap);
                 hpriv->start_engine(ap);
         }
 
         sata_pmp_error_handler(ap);
 
         if (!ata_dev_enabled(ap->link.device))
-                ahci_stop_engine(ap);
+                hpriv->stop_engine(ap);
 }
 EXPORT_SYMBOL_GPL(ahci_error_handler);
 
@@ -2129,7 +2133,7 @@ static void ahci_set_aggressive_devslp(struct ata_port *ap, bool sleep)
                 return;
 
         /* set DITO, MDAT, DETO and enable DevSlp, need to stop engine first */
-        rc = ahci_stop_engine(ap);
+        rc = hpriv->stop_engine(ap);
         if (rc)
                 return;
 
@@ -2189,7 +2193,7 @@ static void ahci_enable_fbs(struct ata_port *ap)
                 return;
         }
 
-        rc = ahci_stop_engine(ap);
+        rc = hpriv->stop_engine(ap);
         if (rc)
                 return;
 
@@ -2222,7 +2226,7 @@ static void ahci_disable_fbs(struct ata_port *ap)
                 return;
         }
 
-        rc = ahci_stop_engine(ap);
+        rc = hpriv->stop_engine(ap);
         if (rc)
                 return;