From 8cd1bd7eb4ab5fb5ffb77b5a648c92be7d62aaff Mon Sep 17 00:00:00 2001
From: ian <ian>
Date: Sat, 12 Jan 2008 03:32:25 +0000
Subject: [PATCH] new NOPOINT command to get rid of FAULT/POINT race

---
 TODO                   |  3 ---
 cebpic/README.protocol |  9 ++++++++-
 detpic/points.asm      | 13 +++++++++++--
 hostside/cdumgr.c      |  4 ++++
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/TODO b/TODO
index 902e32b..f67896d 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,3 @@
-race between cdu off (due to watchdog or short) and points
-
-
 layout polarity diagram colourful segment encoding:
  make moveable feature selection in subseg2display bitwise rather than
   setwise
diff --git a/cebpic/README.protocol b/cebpic/README.protocol
index da40540..0860a07 100644
--- a/cebpic/README.protocol
+++ b/cebpic/README.protocol
@@ -24,7 +24,7 @@ From host to PIC:
  > 0 0010 000             (10)	OFF	  Power off
 
 ;> 00000000                     CRASHED   Acknowledge panic, go to readout mode
-;> 00001002               (0a)	TELLMODE  Confirm mode - say HELLO or CRASHED
+;> 00001010               (0a)	TELLMODE  Confirm mode - say HELLO or CRASHED
 ;                                          if crashed, undoes the effect of ack
 
 ; In crash readout mode:
@@ -63,6 +63,7 @@ From PIC to host:
  < 0 000 1001             (HT)  HELLO	  I am booted
  < 0 000 1011             (VT)  AAARGH	  Followed by debug chars (only)
  < 0 000 1101             (CR)  WTIMEOUT  Watchdog timeout happened
+ < 0 000 1110             (SO)  NOPOINT   Point fired when CDU off
  < 0 000 0111             (BEL) FAULT	  Fault exists
  < 0 000 0110             (ACK) FIXED	  Fault now fixed
  < 0 0100 PPP             (20+)	POINTED	  Point change done using capacitor P
@@ -155,6 +156,12 @@ not check that the received P value is 0; they may simply assume it).
 	is recharging  <----POINTED----  Point is changing
 
 
+If the CDU is turned off (the disabled and fault states from the power
+state diagram, above), a POINT command will not result in a panic but
+rather produce only an immediate NOPOINT message.  (This must not be a
+panic because the POINT command may already be en-route when a FAULT
+occurs.)
+
 
 PING and PONG
 -------------
diff --git a/detpic/points.asm b/detpic/points.asm
index ac50cff..01555b1 100644
--- a/detpic/points.asm
+++ b/detpic/points.asm
@@ -285,7 +285,7 @@ command_point @
 	bra	command_point_busy
 
 	tst_f_ifnz cducharging
-	bra	command_point_cduempty
+	bra	command_point_ifcduempty
 
 	swap_fw	POSTINC0		; W =		0SSS 1010
 	and_lw	0x70			; W =		0SSS 0000
@@ -311,7 +311,16 @@ command_point @
 
 command_point_badmsg panic morse_PX
 command_point_busy panic morse_PB
-command_point_cduempty panic morse_PC
+
+;----------
+command_point_ifcduempty
+	pinlat_ifh p0_cdu_enable
+	bra	command_point_cducharging
+	; state `Charging' but not really since it's disabled, ie Off:
+	mov_lw	b'00001110' ; POINTED
+	goto	serial_addbyte
+
+command_point_cducharging panic morse_PC
 
 ;----------
 command_point_ifslave
diff --git a/hostside/cdumgr.c b/hostside/cdumgr.c
index 089d954..db6f8ba 100644
--- a/hostside/cdumgr.c
+++ b/hostside/cdumgr.c
@@ -14,3 +14,7 @@ void on_pic_pointed(const PicInsnInfo *pii, const PicInsn *pi, int objnum) {
   if (sta_state <= Sta_Settling) return;
   /* fixme do something here */
 }
+
+void on_pic_nopoint(const PicInsnInfo *pii, const PicInsn *pi, int objnum) {
+  /* fixme perhaps log this if it was unexpected */
+}
-- 
2.30.2