From 5981ec44e4522f68921c4b46f65bfed3e2eaaa42 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Thu, 1 May 2025 00:54:48 +0200
Subject: [PATCH] avr: only write COM address if changed to reduce EEPROM wear.

---
 avr/apps/network/main.asm | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/avr/apps/network/main.asm b/avr/apps/network/main.asm
index d7f6070..45dfd2f 100644
--- a/avr/apps/network/main.asm
+++ b/avr/apps/network/main.asm
@@ -26,7 +26,7 @@
 
 
 .equ APP_NETWORK_ADDRESS_RANGE_BEGIN = 1
-.equ APP_NETWORK_ADDRESS_RANGE_END   = 192
+.equ APP_NETWORK_ADDRESS_RANGE_END   = 191
 
 .equ APP_NETWORK_REBOOT_TIME_100MS   = 20
 
@@ -207,18 +207,23 @@ appNetworkHandleStateHaveAddress1:
 appNetworkHandleStateHaveAddress2:
   ldi r16, APP_NETWORK_STATE_UP
   std Y+NET_IFACE_OFFS_STATUS, r16
+  ldi r16, APP_NETWORK_TIMER_100MS
+  std Y+NET_IFACE_OFFS_STATETIMER, r16
   ldd r16, Y+NET_IFACE_OFFS_RANGE_BEGIN  ; set interface address
+  ldd r17, Y+NET_IFACE_OFFS_ADDRESS
+  cp r16, r17
+  breq appNetworkHandleStateHaveAddress2_end
+  ; store new address in IFACE and in EEPROM
   std Y+NET_IFACE_OFFS_ADDRESS, r16
-
-  in r15, SREG
   push r15
+    in r15, SREG
     cli
     ldi xl, LOW(EEPROM_OFFS_COMADDR)
     ldi xh, HIGH(EEPROM_OFFS_COMADDR)
     rcall Utils_WriteEepromIncr            ; write address to EEPROM
+    out SREG, r15
   pop r15
-  out SREG, r15
-
+appNetworkHandleStateHaveAddress2_end:
   ret
 
 
@@ -323,16 +328,16 @@ appNetworkHandleMsgDenyAddr:
   ; check state
   ldd r16, Y+NET_IFACE_OFFS_STATUS
   cpi r16, APP_NETWORK_STATE_UP
-  breq appNetworkHandleMsgDenyAddr_end ; ignore (our network stack is up)
+  breq appNetworkHandleMsgDenyAddr_end  ; ignore (our network stack is up)
   ; still setting up address, check whether the last one is denied now
   ldd r16, Y+NET_IFACE_OFFS_RANGE_BEGIN
-  cp r19, r16                          ; our claimed address?
-  brne appNetworkHandleMsgDenyAddr_end ; nope, jump
+  cp r19, r16                           ; our claimed address?
+  brne appNetworkHandleMsgDenyAddr_end  ; nope, jump
   ; try next address (if any left)
   ldd r17, Y+NET_IFACE_OFFS_RANGE_END
-  inc r16
-  cp r16, r17
-  brcs appNetworkHandleMsgDenyAddr_claimNext
+  inc r16                               ; RANGE_BEGIN+1
+  cp r17, r16                           ; smaller than or equal to RANGE_END?
+  brcc appNetworkHandleMsgDenyAddr_claimNext
   ; out of addresses, start completely new after some waiting time
   rcall appNetworkResetState
   ldi r16, 200                          ; wait for 20s before trying whole process again
@@ -397,6 +402,7 @@ appNetworkResetState:
   cpi r16, 0xff
   breq appNetworkResetState_setRangeEnd
   std Y+NET_IFACE_OFFS_RANGE_BEGIN, r16
+  std Y+NET_IFACE_OFFS_ADDRESS, r16          ; preset address from EEPROM
 appNetworkResetState_setRangeEnd:
   ldi r16, APP_NETWORK_ADDRESS_RANGE_END     ; last possible address+1
   std Y+NET_IFACE_OFFS_RANGE_END, r16
@@ -409,17 +415,17 @@ appNetworkResetState_setRangeEnd:
 ; @routine appNetworkGetAddressFromEeprom
 ;
 ; @return R16 address from EEPROM
-; @clobbers R15, X
+; @clobbers X
 
 appNetworkGetAddressFromEeprom:
-  ldi xl, LOW(EEPROM_OFFS_COMADDR)
-  ldi xh, HIGH(EEPROM_OFFS_COMADDR)
-  in r15, SREG
   push r15
+    in r15, SREG
     cli
+    ldi xl, LOW(EEPROM_OFFS_COMADDR)
+    ldi xh, HIGH(EEPROM_OFFS_COMADDR)
     rcall Utils_ReadEepromIncr             ; (R16)
+    out SREG, r15
   pop r15
-  out SREG, r15
   ret
 ; @end