From 1a41e40714d5e401cfd4f9fd37fc28d2697057f0 Mon Sep 17 00:00:00 2001
From: Gwendal <gwendal.raoul@wirepas.com>
Date: Wed, 4 Dec 2019 14:55:30 +0100
Subject: [PATCH 1/2] Serial write Linux: patch for segger chip

Patch to workaround faulty segger chip of nordic kit.
---
 lib/platform/linux/serial.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/lib/platform/linux/serial.c b/lib/platform/linux/serial.c
index 36639e6..d38623b 100644
--- a/lib/platform/linux/serial.c
+++ b/lib/platform/linux/serial.c
@@ -21,6 +21,17 @@
 
 static int fd = -1;
 
+// This define modifies the write function to avoid issues with
+// Nordic Evaluation Kit connected through USB with a faulty
+// segger chip (for the USB to serial conversion). In fact the
+// declared USB buffer size seems wrong (512 instead of 64 bytes)
+// resulting in truncated packets if the lib send bigger packets than
+// 64 bytes. Splitting them before sending seems to workaround the issue
+// If not in this situation, the following line can be commented
+// Having it all the time even if accessing a real serial device shouldn't
+// impact performances
+#define PATCH_SEGGER_CHIP
+
 static int set_interface_attribs(int fd, unsigned long bitrate, int parity)
 {
     struct termios tty;
@@ -198,6 +209,7 @@ int Serial_read(unsigned char * c, unsigned int timeout_ms)
     }
 }
 
+#define WRITE_CHUNK_SIZE 64
 int Serial_write(const unsigned char * buffer, unsigned int buffer_size)
 {
     if (fd < 0)
@@ -206,5 +218,25 @@ int Serial_write(const unsigned char * buffer, unsigned int buffer_size)
         return -1;
     }
 
+#ifdef PATCH_SEGGER_CHIP
+    unsigned int written = 0;
+    // Send buffer in 64 bytes chunks
+    while (buffer_size > 0)
+    {
+        unsigned int size = buffer_size > WRITE_CHUNK_SIZE ? WRITE_CHUNK_SIZE : buffer_size;
+        unsigned int partial_written;
+
+        partial_written = write(fd, buffer + written, size);
+        if (partial_written < 0)
+        {
+            return partial_written;
+        }
+
+        written += partial_written;
+        buffer_size -= partial_written;
+    }
+    return written;
+#else
     return write(fd, buffer, buffer_size);
+#endif  //PATCH_SEGGER_CHIP
 }

From 8886923df535dae93c50c0549923d64580bf7c65 Mon Sep 17 00:00:00 2001
From: Gwendal <47559821+GwendalRaoul@users.noreply.github.com>
Date: Wed, 4 Dec 2019 15:28:11 +0100
Subject: [PATCH 2/2] Update wrong type

---
 lib/platform/linux/serial.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/platform/linux/serial.c b/lib/platform/linux/serial.c
index d38623b..175772b 100644
--- a/lib/platform/linux/serial.c
+++ b/lib/platform/linux/serial.c
@@ -224,9 +224,7 @@ int Serial_write(const unsigned char * buffer, unsigned int buffer_size)
     while (buffer_size > 0)
     {
         unsigned int size = buffer_size > WRITE_CHUNK_SIZE ? WRITE_CHUNK_SIZE : buffer_size;
-        unsigned int partial_written;
-
-        partial_written = write(fd, buffer + written, size);
+        int partial_written = write(fd, buffer + written, size);
         if (partial_written < 0)
         {
             return partial_written;