Change order of TX buffer fill to ensure in-order sending of frames.

techie66 · techie66 · commit c8556d5c1b92 · 2025-02-02T11:45:28.000-05:00
diff --git a/src/mcp2515_can.cpp b/src/mcp2515_can.cpp
@@ -1032,7 +1032,7 @@ byte mcp2515_can::mcp2515_getNextFreeTXBuf(byte* txbuf_n) {               // get
     }
 
     // check all 3 TX-Buffers except reserved
-    for (i = 0; i < MCP_N_TXBUFFERS - nReservedTx; i++) {
+    for (i = MCP_N_TXBUFFERS - nReservedTx; i >= 0; i--) {
         if ((status & txStatusPendingFlag(i)) == 0) {
             *txbuf_n = txCtrlReg(i) + 1;                                   // return SIDH-address of Buffer
             mcp2515_modifyRegister(MCP_CANINTF, txIfFlag(i), 0);

Original file line number	Diff line number	Diff line change
`@@ -1032,7 +1032,7 @@ byte mcp2515_can::mcp2515_getNextFreeTXBuf(byte* txbuf_n) { // get`
`1032`	`1032`	`}`
`1033`	`1033`
`1034`	`1034`	`// check all 3 TX-Buffers except reserved`
`1035`		`- for (i = 0; i < MCP_N_TXBUFFERS - nReservedTx; i++) {`
	`1035`	`+ for (i = MCP_N_TXBUFFERS - nReservedTx; i >= 0; i--) {`
`1036`	`1036`	`if ((status & txStatusPendingFlag(i)) == 0) {`
`1037`	`1037`	`*txbuf_n = txCtrlReg(i) + 1; // return SIDH-address of Buffer`
`1038`	`1038`	`mcp2515_modifyRegister(MCP_CANINTF, txIfFlag(i), 0);`