libahci: Allow drivers to override start_engine

Allwinner A10 and A20 ARM SoCs have an AHCI sata controller which needs a
special register to be poked before starting the DMA engine.

This register gets reset on an ahci_stop_engine call, so there is no other
place then ahci_start_engine where this poking can be done.

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

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/ata/sata_highbank.c b/drivers/ata/sata_highbank.c
index 5a68b7b8f491..d4df0bf9a55a 100644
--- a/drivers/ata/sata_highbank.c
+++ b/drivers/ata/sata_highbank.c
@@ -402,6 +402,7 @@ static int ahci_highbank_hardreset(struct ata_link *link, unsigned int *class,
         static const unsigned long timing[] = { 5, 100, 500};
         struct ata_port *ap = link->ap;
         struct ahci_port_priv *pp = ap->private_data;
+        struct ahci_host_priv *hpriv = ap->host->private_data;
         u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
         struct ata_taskfile tf;
         bool online;
@@ -430,7 +431,7 @@ static int ahci_highbank_hardreset(struct ata_link *link, unsigned int *class,
                         break;
         } while (!online && retry--);
 
-        ahci_start_engine(ap);
+        hpriv->start_engine(ap);
 
         if (online)
                 *class = ahci_dev_classify(ap);