1 files changed, 39 insertions, 8 deletions

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 466d12b7fd46..2d1669c0f6c0 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -318,6 +318,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
         struct list_head resources;
         struct resource io_res;
         struct device *dev = &device->dev;
+        u32 pa_high, pa_low;
         u64 cmd_pa;
         u32 cmd_size;
         u64 rsp_pa;
@@ -345,12 +346,27 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
         if (IS_ERR(priv->cca))
                 return PTR_ERR(priv->cca);
 
-        cmd_pa = ((u64) ioread32(&priv->cca->cmd_pa_high) << 32) |
-                  (u64) ioread32(&priv->cca->cmd_pa_low);
+        /*
+         * PTT HW bug w/a: wake up the device to access
+         * possibly not retained registers.
+         */
+        ret = crb_cmd_ready(dev, priv);
+        if (ret)
+                return ret;
+
+        pa_high = ioread32(&priv->cca->cmd_pa_high);
+        pa_low  = ioread32(&priv->cca->cmd_pa_low);
+        cmd_pa = ((u64)pa_high << 32) | pa_low;
         cmd_size = ioread32(&priv->cca->cmd_size);
+
+        dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
+                pa_high, pa_low, cmd_size);
+
         priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size);
-        if (IS_ERR(priv->cmd))
-                return PTR_ERR(priv->cmd);
+        if (IS_ERR(priv->cmd)) {
+                ret = PTR_ERR(priv->cmd);
+                goto out;
+        }
 
         memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8);
         rsp_pa = le64_to_cpu(rsp_pa);
@@ -358,7 +374,8 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
 
         if (cmd_pa != rsp_pa) {
                 priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size);
-                return PTR_ERR_OR_ZERO(priv->rsp);
+                ret = PTR_ERR_OR_ZERO(priv->rsp);
+                goto out;
         }
 
         /* According to the PTP specification, overlapping command and response
@@ -366,12 +383,18 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
          */
         if (cmd_size != rsp_size) {
                 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
-                return -EINVAL;
+                ret = -EINVAL;
+                goto out;
         }
+
         priv->cmd_size = cmd_size;
 
         priv->rsp = priv->cmd;
-        return 0;
+
+out:
+        crb_go_idle(dev, priv);
+
+        return ret;
 }
 
 static int crb_acpi_add(struct acpi_device *device)
@@ -415,7 +438,15 @@ static int crb_acpi_add(struct acpi_device *device)
         if (rc)
                 return rc;
 
-        return crb_init(device, priv);
+        rc  = crb_cmd_ready(dev, priv);
+        if (rc)
+                return rc;
+
+        rc = crb_init(device, priv);
+        if (rc)
+                crb_go_idle(dev, priv);
+
+        return rc;
 }
 
 static int crb_acpi_remove(struct acpi_device *device)