* ser-unix.c (wait_for, hardwire_readchar) [HAVE_TERMIO, HAVE_TERMIOS]:

If the timeout is too big to fit in c_cc[VTIME], then do multiple reads
	to achieve the desired timeout.
	* serial.h (serial_t): Add field timeout_remaining.

gdb/serial.h

@@ -33,6 +33,9 @@ struct _serial_t
   unsigned char *bufp;		/* Current byte */
   unsigned char buf[BUFSIZ];	/* Da buffer itself */
   int current_timeout;		/* (termio{s} only), last value of VTIME */
+  /* ser-unix.c termio{,s} only, we still need to wait for this many more
+     seconds.  */
+  int timeout_remaining;
 };
 
 typedef struct _serial_t *serial_t;