Modifications to drop input buffer content rather than trying to read the axact amoun...

diff --git a/isp_commands.c b/isp_commands.c
index e43f518..7ee167a 100644 (file)
--- a/isp_commands.c
+++ b/isp_commands.c
@@ -126,7 +126,7 @@ int isp_connect(unsigned int crystal_freq, int quiet)
                return -3;
        }
        /* Empty read buffer (echo is on) */
-       isp_serial_read(buf, strlen(SYNCHRO), strlen(SYNCHRO));
+       isp_serial_empty_buffer();
        /* Read reply (OK) */
        isp_serial_read(buf, REP_BUFSIZE, strlen(SYNCHRO_OK));
        if (strncmp(SYNCHRO_OK, buf, strlen(SYNCHRO_OK)) != 0) {
@@ -137,7 +137,7 @@ int isp_connect(unsigned int crystal_freq, int quiet)
        /* Documentation says we should send crystal frequency .. sending anything is OK */
        isp_serial_write(freq, strlen(freq));
        /* Empty read buffer (echo is on) */
-       isp_serial_read(buf, strlen(freq), strlen(freq));
+       isp_serial_empty_buffer();
        /* Read reply (OK) */
        isp_serial_read(buf, REP_BUFSIZE, strlen(SYNCHRO_OK));
        if (strncmp(SYNCHRO_OK, buf, strlen(SYNCHRO_OK)) != 0) {
@@ -148,7 +148,7 @@ int isp_connect(unsigned int crystal_freq, int quiet)
        /* Turn off echo */
        isp_serial_write(SYNCHRO_ECHO_OFF, strlen(SYNCHRO_ECHO_OFF));
        /* Empty read buffer (echo still on) */
-       isp_serial_read(buf, strlen(SYNCHRO_ECHO_OFF), strlen(SYNCHRO_ECHO_OFF));
+       isp_serial_empty_buffer();
        /* Read eror code for command */
        isp_serial_read(buf, REP_BUFSIZE, 3);
 

diff --git a/isp_utils.c b/isp_utils.c
index 6409375..4bd075d 100644 (file)
--- a/isp_utils.c
+++ b/isp_utils.c
@@ -143,6 +143,41 @@ int isp_serial_write(const char* buf, unsigned int buf_size)
        return nb;
 }
 
+static char next_read_char = 0;
+void isp_serial_empty_buffer()
+{
+       int nb = 0;
+       char unused = 0;
+       unsigned int loops = 0; /* Used to create a timeout */
+
+       do {
+               nb = read(serial_fd, &unused, 1);
+               if (nb < 0) {
+                       if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) {
+                               if (loops++ > 100) {
+                                       break; /* timeout at 500ms */
+                               }
+                               usleep( 5000 );
+                               continue;
+                       }
+                       perror("Serial read error");
+                       return;
+               } else if (nb == 0) {
+                       printf("serial_read: end of file !!!!\n");
+                       return;
+               }
+       } while ((unused != '\r') && (unused != '\n'));
+
+       /* This should be improved by reading ALL \r and \n */
+       if (unused == '\r') {
+               nb = read(serial_fd, &unused, 1);
+       }
+       if (unused == '\n') {
+               return;
+       }
+       next_read_char = unused;
+}
+
 /* Try to read at least "min_read" characters from the serial line.
  * Returns -1 on error, 0 on end of file, or read count otherwise.
  */
@@ -156,6 +191,10 @@ int isp_serial_read(char* buf, unsigned int buf_size, unsigned int min_read)
                printf("serial_read: buffer too small for min read value.\n");
                return -3;
        }
+       if (next_read_char != 0) {
+               buf[count++] = next_read_char;
+               next_read_char = 0;
+       }
 
        do {
                nb = read(serial_fd, &buf[count], (buf_size - count));

diff --git a/isp_utils.h b/isp_utils.h
index 5a59186..521ae69 100644 (file)
--- a/isp_utils.h
+++ b/isp_utils.h
@@ -30,6 +30,7 @@ void isp_serial_close(void);
 /* Simple write() wrapper, with trace if enabled */
 int isp_serial_write(const char* buf, unsigned int buf_size);
 
+void isp_serial_empty_buffer();
 /* Try to read at least "min_read" characters from the serial line.
  * Returns -1 on error, 0 on end of file, or read count otherwise.
  */