Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

[pandora-kernel.git] / drivers / char / hvc_vio.c

diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c
index f5212eb..9add81c 100644 (file)
--- a/drivers/char/hvc_vio.c
+++ b/drivers/char/hvc_vio.c
@@ -31,10 +31,13 @@
 
 #include <linux/types.h>
 #include <linux/init.h>
+
 #include <asm/hvconsole.h>
 #include <asm/vio.h>
 #include <asm/prom.h>
 
+#include "hvc_console.h"
+
 char hvc_driver_name[] = "hvc_console";
 
 static struct vio_device_id hvc_driver_table[] __devinitdata = {
@@ -48,6 +51,14 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
        unsigned long got;
        int i;
 
+       /*
+        * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
+        * so we play safe and avoid the situation where got > count which could
+        * overload the flip buffer.
+        */
+       if (count < SIZE_VIO_GET_CHARS)
+               return -EAGAIN;
+
        got = hvc_get_chars(vtermno, buf, count);
 
        /*