1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/ata/pata_pcmcia.c b/drivers/ata/pata_pcmcia.c
index 820332a7ec7b..171da0aeb65f 100644
--- a/drivers/ata/pata_pcmcia.c
+++ b/drivers/ata/pata_pcmcia.c
@@ -54,6 +54,39 @@ struct ata_pcmcia_info {
         dev_node_t      node;
 };
 
+/**
+ *      pcmcia_set_mode -       PCMCIA specific mode setup
+ *      @ap: Port
+ *      @r_failed_dev: Return pointer for failed device
+ *
+ *      Perform the tuning and setup of the devices and timings, which
+ *      for PCMCIA is the same as any other controller. We wrap it however
+ *      as we need to spot hardware with incorrect or missing master/slave
+ *      decode, which alas is embarrassingly common in the PC world
+ */
+
+static int pcmcia_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
+{
+        struct ata_device *master = &ap->device[0];
+        struct ata_device *slave = &ap->device[1];
+
+        if (!ata_dev_enabled(master) || !ata_dev_enabled(slave))
+                return ata_do_set_mode(ap, r_failed_dev);
+
+        if (memcmp(master->id + ATA_ID_FW_REV,  slave->id + ATA_ID_FW_REV,
+                           ATA_ID_FW_REV_LEN + ATA_ID_PROD_LEN) == 0)
+        {
+                /* Suspicious match, but could be two cards from
+                   the same vendor - check serial */
+                if (memcmp(master->id + ATA_ID_SERNO, slave->id + ATA_ID_SERNO,
+                           ATA_ID_SERNO_LEN) == 0 && master->id[ATA_ID_SERNO] >> 8) {
+                        ata_dev_printk(slave, KERN_WARNING, "is a ghost device, ignoring.\n");
+                        ata_dev_disable(slave);
+                }
+        }
+        return ata_do_set_mode(ap, r_failed_dev);
+}
+
 static struct scsi_host_template pcmcia_sht = {
         .module                 = THIS_MODULE,
         .name                   = DRV_NAME,
@@ -73,6 +106,7 @@ static struct scsi_host_template pcmcia_sht = {
 };
 
 static struct ata_port_operations pcmcia_port_ops = {
+        .set_mode       = pcmcia_set_mode,
         .port_disable   = ata_port_disable,
         .tf_load        = ata_tf_load,
         .tf_read        = ata_tf_read,