diff --git a/drivers/staging/rdma/hfi1/eprom.c b/drivers/staging/rdma/hfi1/eprom.c
index fb620c97f592dffe4a72c0b1bb6044bbacc2b890..8104a1121bf2ae4b9f32b7276b0935ba4829c616 100644
--- a/drivers/staging/rdma/hfi1/eprom.c
+++ b/drivers/staging/rdma/hfi1/eprom.c
@@ -353,21 +353,26 @@ static inline u32 extract_rstart(u32 composite)
  *
  * Return 0 on success, -ERRNO on error
  */
-int handle_eprom_command(const struct hfi1_cmd *cmd)
+int handle_eprom_command(struct file *fp, const struct hfi1_cmd *cmd)
 {
 	struct hfi1_devdata *dd;
 	u32 dev_id;
 	u32 rlen;	/* range length */
 	u32 rstart;	/* range start */
+	int i_minor;
 	int ret = 0;
 
 	/*
-	 * The EPROM is per-device, so use unit 0 as that will always
-	 * exist.
+	 * Map the device file to device data using the relative minor.
+	 * The device file minor number is the unit number + 1.  0 is
+	 * the generic device file - reject it.
 	 */
-	dd = hfi1_lookup(0);
+	i_minor = iminor(file_inode(fp)) - HFI1_USER_MINOR_BASE;
+	if (i_minor <= 0)
+		return -EINVAL;
+	dd = hfi1_lookup(i_minor - 1);
 	if (!dd) {
-		pr_err("%s: cannot find unit 0!\n", __func__);
+		pr_err("%s: cannot find unit %d!\n", __func__, i_minor);
 		return -EINVAL;
 	}
 
diff --git a/drivers/staging/rdma/hfi1/eprom.h b/drivers/staging/rdma/hfi1/eprom.h
index 64a64276be8193b59f36fc73ce40dee491ace234..5a61ba3ba8102ee182c1a0b0fdcb940b43a58cd1 100644
--- a/drivers/staging/rdma/hfi1/eprom.h
+++ b/drivers/staging/rdma/hfi1/eprom.h
@@ -52,4 +52,4 @@ struct hfi1_cmd;
 struct hfi1_devdata;
 
 int eprom_init(struct hfi1_devdata *dd);
-int handle_eprom_command(const struct hfi1_cmd *cmd);
+int handle_eprom_command(struct file *fp, const struct hfi1_cmd *cmd);
diff --git a/drivers/staging/rdma/hfi1/file_ops.c b/drivers/staging/rdma/hfi1/file_ops.c
index 2de9032857d33725d92973431f65a78a49c41384..cc681f7bc5705a80d0d3808a1c163484d843d75b 100644
--- a/drivers/staging/rdma/hfi1/file_ops.c
+++ b/drivers/staging/rdma/hfi1/file_ops.c
@@ -409,7 +409,7 @@ static ssize_t hfi1_file_write(struct file *fp, const char __user *data,
 	case HFI1_CMD_EP_ERASE_RANGE:
 	case HFI1_CMD_EP_READ_RANGE:
 	case HFI1_CMD_EP_WRITE_RANGE:
-		ret = handle_eprom_command(&cmd);
+		ret = handle_eprom_command(fp, &cmd);
 		break;
 	}