Fixed random pause/hesitation when printing (bigtreetech#2827)

* Fixed random pause/hesitation when printing

* added volatile type for wIndex on Serial.h

* minor cleanup

TFT/src/User/API/Printing.c

@@ -105,7 +105,7 @@ void loopBreakToCondition(CONDITION_CALLBACK condCallback)
   // from that command. Than another "M108" will be sent to unlock a next possible blocking command.
   // This way enough "M108" will be sent to unlock all possible blocking command(s) (ongoing or enqueued) but not too much and
   // not too fast one after another to overload/overrun the serial communication
-  TASK_LOOP_WHILE(condCallback(), if (infoHost.rx_ok[SERIAL_PORT] == true) sendEmergencyCmd("M108\n"))
+  TASK_LOOP_WHILE(condCallback(), if (Serial_Available(SERIAL_PORT) != 0) sendEmergencyCmd("M108\n"));
 
   // remove any enqueued command that could come from a supplementary serial port or TFT media
   // (if printing from remote host or TFT media) during the loop above

TFT/src/User/API/SerialConnection.c

@@ -112,7 +112,7 @@ void Serial_Forward(SERIAL_PORT_INDEX portIndex, const char * msg)
     Serial_Put(SERIAL_DEBUG_PORT, msg);
   #endif
 
-  uint8_t portCount = SERIAL_PORT_COUNT;                      // by default, select all the serial ports
+  uint8_t portCount = SERIAL_PORT_COUNT;  // by default, select all the serial ports
 
   if (portIndex == ALL_PORTS)         // if ALL_PORTS, forward the message to all the enabled serial ports
     portIndex = PORT_1;
@@ -136,55 +136,52 @@ void Serial_Forward(SERIAL_PORT_INDEX portIndex, const char * msg)
   }
 }
 
+uint16_t Serial_Available(SERIAL_PORT_INDEX portIndex)
+{
+  if (!WITHIN(portIndex, PORT_1, SERIAL_PORT_COUNT - 1))
+    return 0;
+
+  return (dmaL1Data[portIndex].cacheSize + dmaL1Data[portIndex].wIndex - dmaL1Data[portIndex].rIndex) % dmaL1Data[portIndex].cacheSize;
+}
+
 uint16_t Serial_Get(SERIAL_PORT_INDEX portIndex, char * buf, uint16_t bufSize)
 {
   // if port index is out of range or no data to read from L1 cache
-  if (!WITHIN(portIndex, PORT_1, SERIAL_PORT_COUNT - 1) || !infoHost.rx_ok[portIndex])
+  if (!WITHIN(portIndex, PORT_1, SERIAL_PORT_COUNT - 1) || dmaL1Data[portIndex].flag == dmaL1Data[portIndex].wIndex)
     return 0;
 
-  // make access to dinamically changed (by L1 cache's interrupt handler) variables/attributes faster and also reducing the code
   DMA_CIRCULAR_BUFFER * dmaL1Data_ptr = &dmaL1Data[portIndex];
-  uint16_t * wIndex_ptr = &dmaL1Data_ptr->wIndex;
 
-  // L1 cache's reading index (not dinamically changed (by L1 cache's interrupt handler) variables/attributes)
+  // make a static access to dynamically changed (by L1 cache's interrupt handler) variables/attributes
+  uint16_t wIndex = dmaL1Data_ptr->wIndex;
+
+  // L1 cache's reading index (not dynamically changed (by L1 cache's interrupt handler) variables/attributes)
   uint16_t rIndex = dmaL1Data_ptr->rIndex;
 
-  while (dmaL1Data_ptr->cache[rIndex] == ' ' && rIndex != *wIndex_ptr)  // remove leading empty space, if any
+  while (dmaL1Data_ptr->cache[rIndex] == ' ' && rIndex != wIndex)  // remove leading empty space, if any
   {
     rIndex = (rIndex + 1) % dmaL1Data_ptr->cacheSize;
   }
 
-  for (uint16_t i = 0; i < (bufSize - 1) && rIndex != *wIndex_ptr; )  // retrieve data until buf is full or L1 cache is empty
+  for (uint16_t i = 0; i < (bufSize - 1) && rIndex != wIndex; )  // retrieve data until buf is full or L1 cache is empty
   {
     buf[i] = dmaL1Data_ptr->cache[rIndex];
     rIndex = (rIndex + 1) % dmaL1Data_ptr->cacheSize;
 
     if (buf[i++] == '\n')  // if data end marker is found
     {
-      buf[i] = '\0';                   // end character
-      dmaL1Data_ptr->rIndex = rIndex;  // update queue's index
-
-      if (rIndex == dmaL1Data_ptr->wIndex)  // if L1 cache is empty, mark the port as containing no more data
-        infoHost.rx_ok[portIndex] = false;
+      buf[i] = '\0';                                         // end character
+      dmaL1Data_ptr->flag = dmaL1Data_ptr->rIndex = rIndex;  // update queue's custom flag and reading index with rIndex
 
       return i;  // return the number of bytes stored in buf
     }
   }
 
   // if here, a partial message is present on the L1 cache (message not terminated by "\n").
-  // We temporary skip the message until it is fully received
-  //
-  // NOTES:
-  //   - this scenario typically happens when the TFT receives a burst of messages (e.g. the output for "M420 V1 T1").
-  //     The first fully received message (terminated by "\n") is enough to trigger the L1 cache as available
-  //     (infoHost.rx_ok[portIndex] set to "true") for reading
-  //   - it is more safe to leave the following code line commented out just to avoid any possibility the
-  //     L1 cache's interrupt handler is receiving (and triggering L1 cache as available) in the meanwhile
-  //     (more safe to perform an active polling on the next invokation of this function than the possibility
-  //     to not be able to read the message (if infoHost.rx_ok[portIndex] is found set to "false") until a
-  //     next message (if any) becomes available)
-  //
-//  infoHost.rx_ok[portIndex] = false;  // mark the port as containing no more (or partial) data
+  // We temporary skip the message until it is fully received updating also dmaL1Data_ptr->flag to
+  // prevent to read again (multiple times) the same partial message on next function invokation
+
+  dmaL1Data_ptr->flag = wIndex;  // update queue's custom flag with wIndex
 
   return 0;  // return the number of bytes stored in buf
 }

TFT/src/User/API/SerialConnection.h

@@ -62,6 +62,12 @@ void Serial_DeInit(SERIAL_PORT_INDEX portIndex);
 //     - specific port index: specific serial port
 void Serial_Forward(SERIAL_PORT_INDEX portIndex, const char * msg);
 
+// retrieve the number of bytes available on the provided serial port:
+//   - portIndex: index of serial port
+//
+//   - return value: number of bytes available on serial port
+uint16_t Serial_Available(SERIAL_PORT_INDEX portIndex);
+
 // retrieve a message from the provided serial port, if any:
 //   - portIndex: index of serial port where data are read from
 //   - buf: buffer where data are stored

TFT/src/User/Hal/gd32f20x/Serial.c

@@ -69,15 +69,13 @@ void Serial_DMA_Config(uint8_t port)
 
 void Serial_ClearData(uint8_t port)
 {
-  dmaL1Data[port].rIndex = dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize = 0;
+  dmaL1Data[port].wIndex = dmaL1Data[port].rIndex = dmaL1Data[port].flag = dmaL1Data[port].cacheSize = 0;
 
   if (dmaL1Data[port].cache != NULL)
   {
     free(dmaL1Data[port].cache);
     dmaL1Data[port].cache = NULL;
   }
-
-  infoHost.rx_ok[port] = false;
 }
 
 void Serial_Config(uint8_t port, uint16_t cacheSize, uint32_t baudrate)
@@ -109,11 +107,6 @@ void USART_IRQHandler(uint8_t port)
     USART_DATA(Serial[port].uart);
 
     dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize - DMA_CHCNT(Serial[port].dma_stream, Serial[port].dma_channel);
-    uint16_t wIndex = (dmaL1Data[port].wIndex == 0) ? dmaL1Data[port].cacheSize : dmaL1Data[port].wIndex;
-    if (dmaL1Data[port].cache[wIndex - 1] == '\n')  // Receive completed
-    {
-      infoHost.rx_ok[port] = true;
-    }
   }
 }
 

TFT/src/User/Hal/gd32f20x/Serial.h

@@ -5,11 +5,12 @@
 #include "variants.h"  // for uint32_t etc...
 #include "uart.h"
 
-typedef struct
+typedef volatile struct  // precautionally declared as volatile due to access from interrupt handler and main thread
 {
   char *cache;
-  uint16_t wIndex;
-  uint16_t rIndex;
+  uint16_t wIndex;  // writing index
+  uint16_t rIndex;  // reading index
+  uint16_t flag;    // custom flag (for custom usage by the application)
   uint16_t cacheSize;
 } DMA_CIRCULAR_BUFFER;
 

TFT/src/User/Hal/stm32f10x/Serial.c

@@ -41,15 +41,13 @@ void Serial_DMA_Config(uint8_t port)
 
 void Serial_ClearData(uint8_t port)
 {
-  dmaL1Data[port].rIndex = dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize = 0;
+  dmaL1Data[port].wIndex = dmaL1Data[port].rIndex = dmaL1Data[port].flag = dmaL1Data[port].cacheSize = 0;
 
   if (dmaL1Data[port].cache != NULL)
   {
     free(dmaL1Data[port].cache);
     dmaL1Data[port].cache = NULL;
   }
-
-  infoHost.rx_ok[port] = false;
 }
 
 void Serial_Config(uint8_t port, uint16_t cacheSize, uint32_t baudrate)
@@ -80,11 +78,6 @@ void USART_IRQHandler(uint8_t port)
     Serial[port].uart->DR;
 
     dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize - Serial[port].dma_chanel->CNDTR;
-    uint16_t wIndex = (dmaL1Data[port].wIndex == 0) ? dmaL1Data[port].cacheSize : dmaL1Data[port].wIndex;
-    if (dmaL1Data[port].cache[wIndex - 1] == '\n')  // Receive completed
-    {
-      infoHost.rx_ok[port] = true;
-    }
   }
 }
 

TFT/src/User/Hal/stm32f10x/Serial.h

@@ -5,11 +5,12 @@
 #include "variants.h"  // for uint32_t etc...
 #include "uart.h"
 
-typedef struct
+typedef volatile struct  // precautionally declared as volatile due to access from interrupt handler and main thread
 {
   char *cache;
-  uint16_t wIndex;
-  uint16_t rIndex;
+  uint16_t wIndex;  // writing index
+  uint16_t rIndex;  // reading index
+  uint16_t flag;    // custom flag (for custom usage by the application)
   uint16_t cacheSize;
 } DMA_CIRCULAR_BUFFER;
 

TFT/src/User/Hal/stm32f2_f4xx/Serial.c

@@ -70,15 +70,13 @@ void Serial_DMA_Config(uint8_t port)
 
 void Serial_ClearData(uint8_t port)
 {
-  dmaL1Data[port].rIndex = dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize = 0;
+  dmaL1Data[port].wIndex = dmaL1Data[port].rIndex = dmaL1Data[port].flag = dmaL1Data[port].cacheSize = 0;
 
   if (dmaL1Data[port].cache != NULL)
   {
     free(dmaL1Data[port].cache);
     dmaL1Data[port].cache = NULL;
   }
-
-  infoHost.rx_ok[port] = false;
 }
 
 void Serial_Config(uint8_t port, uint16_t cacheSize, uint32_t baudrate)
@@ -110,11 +108,6 @@ void USART_IRQHandler(uint8_t port)
     Serial[port].uart->DR;
 
     dmaL1Data[port].wIndex = dmaL1Data[port].cacheSize - Serial[port].dma_stream->NDTR;
-    uint16_t wIndex = (dmaL1Data[port].wIndex == 0) ? dmaL1Data[port].cacheSize : dmaL1Data[port].wIndex;
-    if (dmaL1Data[port].cache[wIndex - 1] == '\n')  // Receive completed
-    {
-      infoHost.rx_ok[port] = true;
-    }
   }
 }
 

TFT/src/User/Hal/stm32f2_f4xx/Serial.h

@@ -5,11 +5,12 @@
 #include "variants.h"  // for uint32_t etc...
 #include "uart.h"
 
-typedef struct
+typedef volatile struct  // precautionally declared as volatile due to access from interrupt handler and main thread
 {
   char *cache;
-  uint16_t wIndex;
-  uint16_t rIndex;
+  uint16_t wIndex;  // writing index
+  uint16_t rIndex;  // reading index
+  uint16_t flag;    // custom flag (for custom usage by the application)
   uint16_t cacheSize;
 } DMA_CIRCULAR_BUFFER;
 

TFT/src/User/main.h

@@ -10,13 +10,14 @@ extern "C" {
 #include "variants.h"  // for RCC_ClocksTypeDef
 #include "uart.h"      // for _UART_CNT
 
-#define MAX_MENU_DEPTH 10        // Max sub menu depth
+#define MAX_MENU_DEPTH 10  // max sub menu depth
+
 typedef void (* FP_MENU)(void);
 
 typedef struct
 {
-  FP_MENU menu[MAX_MENU_DEPTH];  // Menu function buffer
-  uint8_t cur;                   // Current menu index in buffer
+  FP_MENU menu[MAX_MENU_DEPTH];  // menu function buffer
+  uint8_t cur;                   // current menu index in buffer
 } MENU;
 
 typedef enum
@@ -30,10 +31,9 @@ typedef enum
 
 typedef struct
 {
-  bool wait;              // Whether wait for Marlin's response
-  bool rx_ok[_UART_CNT];  // Whether receive Marlin's response or get gcode by other UART (ESP3D/OctoPrint)
-  bool connected;         // Whether have connected to Marlin
-  HOST_STATUS status;     // Whether the host is busy in printing execution. (USB serial printing and gcode print from onboard)
+  bool wait;           // whether wait for Marlin's response
+  bool connected;      // whether have connected to Marlin
+  HOST_STATUS status;  // whether the host is busy in printing execution. (USB serial printing and gcode print from onboard)
 } HOST;
 
 typedef struct