From 71167b8adf1148137843be20d1704e5ed0353fbf Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 16 Apr 2015 13:09:29 +0800
Subject: [PATCH] rtio: do not attempt latency compensation in gateware

---
 artiq/gateware/rtio/core.py         |  3 ---
 artiq/gateware/rtio/phy/wishbone.py |  6 ++----
 artiq/gateware/rtio/rtlink.py       | 11 ++++-------
 3 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/artiq/gateware/rtio/core.py b/artiq/gateware/rtio/core.py
index e4818e3af..16c157e0c 100644
--- a/artiq/gateware/rtio/core.py
+++ b/artiq/gateware/rtio/core.py
@@ -318,9 +318,6 @@ class RTIO(Module):
         self.specials += AsyncResetSynchronizer(self.cd_rio,
                                                 self.kcsrs.reset.storage)
 
-        # Latency compensation
-        # TODO
-
         # Managers
         self.submodules.counter = _RTIOCounter(counter_width)
 
diff --git a/artiq/gateware/rtio/phy/wishbone.py b/artiq/gateware/rtio/phy/wishbone.py
index 0d9d06e24..c4c822d3c 100644
--- a/artiq/gateware/rtio/phy/wishbone.py
+++ b/artiq/gateware/rtio/phy/wishbone.py
@@ -4,17 +4,15 @@ from artiq.gateware.rtio import rtlink
 
 
 class RT2WB(Module):
-    def __init__(self, wb, address_width, o_latency=0, i_latency=0):
+    def __init__(self, wb, address_width):
         self.rtlink = rtlink.Interface(
             rtlink.OInterface(
                 flen(wb.dat_w),
                 address_width + 1,
-                latency=o_latency,
                 suppress_nop=False),
             rtlink.IInterface(
                 flen(wb.dat_r),
-                timestamped=False,
-                latency=i_latency)
+                timestamped=False)
             )
 
         # # #
diff --git a/artiq/gateware/rtio/rtlink.py b/artiq/gateware/rtio/rtlink.py
index 0d131b98e..b6d6dc000 100644
--- a/artiq/gateware/rtio/rtlink.py
+++ b/artiq/gateware/rtio/rtlink.py
@@ -3,7 +3,7 @@ from migen.fhdl.std import *
 
 class OInterface:
     def __init__(self, data_width, address_width=0,
-                 fine_ts_width=0, latency=1, suppress_nop=True):
+                 fine_ts_width=0, suppress_nop=True):
         self.stb = Signal()
         self.busy = Signal()
 
@@ -14,7 +14,6 @@ class OInterface:
         if fine_ts_width:
             self.fine_ts = Signal(fine_ts_width)
 
-        self.latency = latency
         self.suppress_nop = suppress_nop
 
     @classmethod
@@ -22,12 +21,12 @@ class OInterface:
         return cls(get_data_width(other),
                    get_address_width(other),
                    get_fine_ts_width(other),
-                   other.latency, other.suppress_nop)
+                   other.suppress_nop)
 
 
 class IInterface:
     def __init__(self, data_width,
-                 timestamped=True, fine_ts_width=0, latency=2):
+                 timestamped=True, fine_ts_width=0):
         self.stb = Signal()
 
         if data_width:
@@ -35,7 +34,6 @@ class IInterface:
         if fine_ts_width:
             self.fine_ts = Signal(fine_ts_width)
 
-        self.latency = latency
         self.timestamped = timestamped
         assert(not fine_ts_width or timestamped)
 
@@ -43,8 +41,7 @@ class IInterface:
     def like(cls, other):
         return cls(get_data_width(other),
                    other.timestamped,
-                   get_fine_ts_width(other),
-                   other.latency)
+                   get_fine_ts_width(other))
 
 
 class Interface: