fix(mcp2515): persist acceptance filter across power cycles

vehicle/OVMS.V3/components/mcp2515/src/mcp2515.cpp

@@ -273,6 +273,14 @@ esp_err_t mcp2515::Start(CAN_mode_t mode, CAN_speed_t speed)
   // And record that we are powered on
   pcp::SetPowerMode(On);
 
+  // Re-apply acceptance filter if one was configured — Start() resets RXMODE to 3
+  // (receive all), which would bypass the hardware filter on every power cycle.
+  if (m_filter_set)
+    {
+    if (SetAcceptanceFilter(m_filter_cfg) != ESP_OK)
+      ESP_LOGE(TAG, "%s: failed to restore acceptance filter after start", this->GetName());
+    }
+
   return ESP_OK;
   }
 
@@ -381,12 +389,23 @@ esp_err_t mcp2515::SetAcceptanceFilter(const mcp2515_filter_config_t& cfg)
     cfg.mask[0].u8[3], cfg.mask[0].u8[2], cfg.mask[0].u8[1],cfg.mask[0].u8[0],
     cfg.mask[1].u8[3], cfg.mask[1].u8[2], cfg.mask[1].u8[1],cfg.mask[1].u8[0]);
 
+  // Set RXMODE=0 (filter-matched receive) on both RX buffers.
+  // Start() hardcodes RXB0CTRL RXMODE=3 (receive all) for backwards compatibility,
+  // which silently bypasses the acceptance filters.  Switch to filtered mode now that
+  // filters are configured.  BUKT (rollover) bit in RXB0CTRL is preserved via mask.
+  // With mask=0 (all bits don't-care) every frame still matches, so callers that pass
+  // all-zero masks get the same promiscuous behaviour as before.
+  m_spibus->spi_cmd(m_spi, buf, 0, 4, CMD_BITMODIFY, REG_RXB0CTRL, 0b01100000, 0b00000000);
+  m_spibus->spi_cmd(m_spi, buf, 0, 4, CMD_BITMODIFY, REG_RXB1CTRL, 0b01100000, 0b00000000);
+
   // Exit config mode
   if (prev_mode != CANCTRL_MODE_CONFIG && ChangeMode(prev_mode) != ESP_OK)
     {
     return ESP_FAIL;
     }
 
+  m_filter_cfg = cfg;
+  m_filter_set = true;
   return ESP_OK;
   }
 

vehicle/OVMS.V3/components/mcp2515/src/mcp2515.h

@@ -110,6 +110,8 @@ class mcp2515 : public canbus
     int m_intpin;
     uint8_t m_last_errflag = 0;
     uint8_t m_canctrl_mode;
+    bool m_filter_set = false;
+    mcp2515_filter_config_t m_filter_cfg = {};
     OvmsMutex m_write_mutex;
     OvmsCommand* m_cmd_canx;
   };

vehicle/OVMS.V3/components/mcp2515/src/mcp2515_regdef.h

@@ -115,6 +115,7 @@
 #define REG_TXB1CTRL            0x40
 #define REG_TXB2CTRL            0x50
 #define REG_RXB0CTRL            0x60
+#define REG_RXB1CTRL            0x70
 
 #define MCP2515_TIMEOUT         100           // Timeout for register verification, in milliseconds