Update stm32xx_emac traces

- Make packet trace optional, can be enabled by enabling macro
  STM32xx_DEEP_TRACE
- Shorten traces during driver initialisation to avoid problems with
  driver startup when soft reset is used.

Author: Arto Kinnunen

connectivity/drivers/emac/TARGET_STM/stm32xx_emac.cpp

@@ -46,6 +46,14 @@
 // #undef TRACE_LEVEL_DEBUG
 // #define TRACE_LEVEL_DEBUG 0
 
+/* To get trace from every packet, enable deep trace macro */
+// #define STM32xx_DEEP_TRACE
+#ifdef STM32xx_DEEP_TRACE
+#define tr_debug_deep(...) tr_debug(__VA_ARGS__)
+#else
+#define tr_debug_deep(...)
+#endif
+
 #if defined(ETH_IP_VERSION_V2)
 #include "lan8742/lan8742.h"
 #include "lwip/memp.h"
@@ -310,7 +318,7 @@ bool STM32_EMAC::low_level_init_successful()
     EthHandle.Init.RxMode = ETH_RXINTERRUPT_MODE;
     EthHandle.Init.ChecksumMode = ETH_CHECKSUM_BY_SOFTWARE;
     EthHandle.Init.MediaInterface = MBED_CONF_STM32_EMAC_ETH_PHY_MEDIA_INTERFACE;
-    tr_info("PHY Addr %u AutoNegotiation %u", EthHandle.Init.PhyAddress, EthHandle.Init.AutoNegotiation);
+    tr_info("power_up: PHY Addr %u AutoNeg %u", EthHandle.Init.PhyAddress, EthHandle.Init.AutoNegotiation);
     tr_debug("MAC Addr %02x:%02x:%02x:%02x:%02x:%02x", MACAddr[0], MACAddr[1], MACAddr[2], MACAddr[3], MACAddr[4], MACAddr[5]);
     tr_info("ETH buffers : %u Rx %u Tx", ETH_RXBUFNB, ETH_TXBUFNB);
 
@@ -576,7 +584,7 @@ int STM32_EMAC::low_level_input(emac_mem_buf_t **buf)
 
     /* get received frame */
     if (HAL_ETH_GetReceivedFrame_IT(&EthHandle) != HAL_OK) {
-        tr_debug("low_level_input no frame");
+        tr_debug_deep("low_level_input no frame");
         return -1;
     }
 
@@ -588,7 +596,7 @@ int STM32_EMAC::low_level_input(emac_mem_buf_t **buf)
     dmarxdesc = EthHandle.RxFrameInfos.FSRxDesc;
 
     if (len > 0 && len <= ETH_RX_BUF_SIZE) {
-        tr_debug("low_level_input len %u", len);
+        tr_debug_deep("low_level_input len %u", len);
         /* Allocate a memory buffer chain from buffer pool */
         *buf = memory_manager->alloc_pool(len, 0);
     }
@@ -877,8 +885,6 @@ void mbed_default_mac_address(char *mac)
 
 bool STM32_EMAC::power_up()
 {
-    tr_info("power_up");
-
     sleep_manager_lock_deep_sleep();
 
     /* Initialize the hardware */