drivers/syslog: Ensure interrupt log doesn't interlace in normal log. Don't call syslog_putc in syslog_default_write because syslog_putc will try to empty the interrupt buffer every time.

drivers/syslog/ramlog.c

@@ -127,9 +127,6 @@ static int     ramlog_poll(FAR struct file *filep, FAR struct pollfd *fds,
 #ifdef CONFIG_RAMLOG_SYSLOG
 static const struct syslog_channel_s g_ramlog_syslog_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_default_write,
-#endif
   ramlog_putc,
   ramlog_putc,
   ramlog_flush

drivers/syslog/syslog.h

@@ -271,26 +271,6 @@ int syslog_putc(int ch);
 
 ssize_t syslog_write(FAR const char *buffer, size_t buflen);
 
-/****************************************************************************
- * Name: syslog_default_write
- *
- * Description:
- *   This provides a default write method for syslog devices that do not
- *   support multiple byte writes  This functions simply loops, outputting
- *   one cahracter at a time.
- *
- * Input Parameters:
- *   buffer - The buffer containing the data to be output
- *   buflen - The number of bytes in the buffer
- *
- * Returned Value:
- *   On success, the number of characters written is returned.  A negated
- *   errno value is returned on any failure.
- *
- ****************************************************************************/
-
-ssize_t syslog_default_write(FAR const char *buffer, size_t buflen);
-
 /****************************************************************************
  * Name: syslog_force
  *

drivers/syslog/syslog_channel.c

@@ -79,9 +79,6 @@ static int syslog_default_flush(void);
 #if defined(CONFIG_RAMLOG_SYSLOG)
 const struct syslog_channel_s g_default_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_default_write,
-#endif
   ramlog_putc,
   ramlog_putc,
   syslog_default_flush
@@ -89,9 +86,6 @@ const struct syslog_channel_s g_default_channel =
 #elif defined(HAVE_LOWPUTC)
 const struct syslog_channel_s g_default_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_default_write,
-#endif
   up_putc,
   up_putc,
   syslog_default_flush
@@ -99,9 +93,6 @@ const struct syslog_channel_s g_default_channel =
 #else
 const struct syslog_channel_s g_default_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_default_write,
-#endif
   syslog_default_putc,
   syslog_default_putc,
   syslog_default_flush

drivers/syslog/syslog_consolechannel.c

@@ -83,9 +83,6 @@ static int syslog_console_force(int ch);
 
 static const struct syslog_channel_s g_syslog_console_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_dev_write,
-#endif
   syslog_dev_putc,
 #ifdef HAVE_LOWPUTC
   up_putc,
@@ -93,6 +90,9 @@ static const struct syslog_channel_s g_syslog_console_channel =
   syslog_console_force,
 #endif
   syslog_dev_flush,
+#ifdef CONFIG_SYSLOG_WRITE
+  syslog_dev_write,
+#endif
 };
 
 /****************************************************************************

drivers/syslog/syslog_devchannel.c

@@ -74,9 +74,6 @@ static int syslog_devchan_force(int ch);
 
 static const struct syslog_channel_s g_syslog_dev_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_dev_write,
-#endif
 #ifdef CONFIG_SYSLOG_CHAR_CRLF
   syslog_devchan_putc,
 #else
@@ -84,6 +81,9 @@ static const struct syslog_channel_s g_syslog_dev_channel =
 #endif
   syslog_devchan_force,
   syslog_dev_flush,
+#ifdef CONFIG_SYSLOG_WRITE
+  syslog_dev_write,
+#endif
 };
 
 /****************************************************************************

drivers/syslog/syslog_filechannel.c

@@ -72,12 +72,12 @@ static int syslog_file_force(int ch);
 
 static const struct syslog_channel_s g_syslog_file_channel =
 {
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_dev_write,
-#endif
   syslog_dev_putc,
   syslog_file_force,
   syslog_dev_flush,
+#ifdef CONFIG_SYSLOG_WRITE
+  syslog_dev_write,
+#endif
 };
 
 /****************************************************************************

drivers/syslog/syslog_write.c

@@ -48,7 +48,7 @@
 #include "syslog.h"
 
 /****************************************************************************
- * Public Functions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
@@ -57,7 +57,7 @@
  * Description:
  *   This provides a default write method for syslog devices that do not
  *   support multiple byte writes  This functions simply loops, outputting
- *   one cahracter at a time.
+ *   one character at a time.
  *
  * Input Parameters:
  *   buffer - The buffer containing the data to be output
@@ -69,21 +69,49 @@
  *
  ****************************************************************************/
 
-ssize_t syslog_default_write(FAR const char *buffer, size_t buflen)
+static ssize_t syslog_default_write(FAR const char *buffer, size_t buflen)
 {
   size_t nwritten;
-  int ret;
 
-  for (nwritten = 0; nwritten < buflen; nwritten++)
+  if (up_interrupt_context() || sched_idletask())
     {
-      int ch = *buffer++;
-      ret = syslog_putc(ch);
-      UNUSED(ret);
+      for (nwritten = 0; nwritten < buflen; nwritten++)
+        {
+#ifdef CONFIG_SYSLOG_INTBUFFER
+          if (up_interrupt_context())
+            {
+              syslog_add_intbuffer(*buffer++);
+            }
+          else
+#endif
+            {
+              DEBUGASSERT(g_syslog_channel->sc_force != NULL);
+              g_syslog_channel->sc_force(*buffer++);
+            }
+        }
+    }
+#ifdef CONFIG_SYSLOG_WRITE
+  else if (g_syslog_channel->sc_write)
+    {
+      nwritten = g_syslog_channel->sc_write(buffer, buflen);
+    }
+#endif
+  else
+    {
+      for (nwritten = 0; nwritten < buflen; nwritten++)
+        {
+          DEBUGASSERT(g_syslog_channel->sc_putc != NULL);
+          g_syslog_channel->sc_putc(*buffer++);
+        }
     }
 
   return buflen;
 }
 
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
 /****************************************************************************
  * Name: syslog_write
  *
@@ -102,22 +130,15 @@ ssize_t syslog_default_write(FAR const char *buffer, size_t buflen)
 
 ssize_t syslog_write(FAR const char *buffer, size_t buflen)
 {
-#ifdef CONFIG_SYSLOG_WRITE
+#ifdef CONFIG_SYSLOG_INTBUFFER
   if (!up_interrupt_context() && !sched_idletask())
     {
-#ifdef CONFIG_SYSLOG_INTBUFFER
       /* Flush any characters that may have been added to the interrupt
        * buffer.
        */
 
       (void)syslog_flush_intbuffer(g_syslog_channel, false);
-#endif
-
-      return g_syslog_channel->sc_write(buffer, buflen);
     }
-  else
 #endif
-    {
-      return syslog_default_write(buffer, buflen);
-    }
+  return syslog_default_write(buffer, buflen);
 }

include/nuttx/syslog/syslog.h

@@ -114,12 +114,12 @@ struct syslog_channel_s
 {
   /* I/O redirection methods */
 
-#ifdef CONFIG_SYSLOG_WRITE
-  syslog_write_t sc_write;  /* Write multiple bytes */
-#endif
   syslog_putc_t  sc_putc;   /* Normal buffered output */
   syslog_putc_t  sc_force;  /* Low-level output for interrupt handlers */
   syslog_flush_t sc_flush;  /* Flush buffered output (on crash) */
+#ifdef CONFIG_SYSLOG_WRITE
+  syslog_write_t sc_write;  /* Write multiple bytes */
+#endif
 
   /* Implementation specific logic may follow */
 };