[PATCH v2] xyz-modem: Allow to configure initial timeout for loadx and loady

["Pali Rohár" <pali@kernel.org>]

Now when loadx and loady commands could be aborted / cancelled by CTRL+C,
allow to configure timeout for initial x/y-modem packet via env variable
$loadxy_timeout and by default use value from new compile-time config
option CONFIG_CMD_LOADXY_TIMEOUT. Value is in seconds and zero value means
infinite timeout. Default value is 90s which is the measured value used
before this change for loadx and loady commands.

Other load commands loadb and loads already waits infinitely. Same behavior
for loadx and loady commands can be achieved by setting $loadxy_timeout or
CONFIG_CMD_LOADXY_TIMEOUT to 0.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
Changes in v2:
* Allow to set timeout via env instead of permanent infinite timeout
---
 cmd/Kconfig       |  7 +++++++
 common/xyzModem.c | 39 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 211ebe9c8783..54af3769a673 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1194,6 +1194,13 @@ config CMD_LOADS
 	help
 	  Load an S-Record file over serial line
 
+config CMD_LOADXY_TIMEOUT
+	int "loadxy_timeout"
+	range 0 2000
+	default 90
+	help
+	  Initial timeout for loadx and loady commands. Zero means infinity.
+
 config CMD_LSBLK
 	depends on BLK
 	bool "lsblk - list block drivers and devices"
diff --git a/common/xyzModem.c b/common/xyzModem.c
index ece25acb183b..700df8edd14a 100644
--- a/common/xyzModem.c
+++ b/common/xyzModem.c
@@ -26,6 +26,7 @@
 #include <stdarg.h>
 #include <u-boot/crc.h>
 #include <watchdog.h>
+#include <env.h>
 
 /* Assumption - run xyzModem protocol over the console port */
 
@@ -50,6 +51,8 @@ static struct
   int len, mode, total_retries;
   int total_SOH, total_STX, total_CAN;
   bool crc_mode, at_eof, tx_ack;
+  bool first_xmodem_packet;
+  ulong initial_time, timeout;
   unsigned long file_length, read_length;
 } xyz;
 
@@ -409,6 +412,18 @@ xyzModem_get_hdr (void)
   return 0;
 }
 
+static
+ulong
+xyzModem_get_initial_timeout (void)
+{
+  /* timeout is in seconds, non-positive timeout value is infinity */
+  const char *timeout_str = env_get("loadxy_timeout");
+  if (timeout_str)
+    return 1000 * simple_strtol(timeout_str, NULL, 10);
+  else
+    return 1000 * CONFIG_CMD_LOADXY_TIMEOUT;
+}
+
 int
 xyzModem_stream_open (connection_info_t * info, int *err)
 {
@@ -439,18 +454,28 @@ xyzModem_stream_open (connection_info_t * info, int *err)
   xyz.total_CAN = 0;
   xyz.read_length = 0;
   xyz.file_length = 0;
+  xyz.first_xmodem_packet = false;
+  xyz.initial_time = get_timer(0);
+  xyz.timeout = xyzModem_get_initial_timeout();
 
   CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
 
   if (xyz.mode == xyzModem_xmodem)
     {
       /* X-modem doesn't have an information header - exit here */
+      xyz.first_xmodem_packet = true;
       xyz.next_blk = 1;
       return 0;
     }
 
-  while (retries-- > 0)
+  while (!(xyz.timeout && get_timer(xyz.initial_time) > xyz.timeout))
     {
+      if (--retries <= 0)
+        {
+          retries = xyzModem_MAX_RETRIES;
+          crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;
+          xyz.crc_mode = true;
+        }
       stat = xyzModem_get_hdr ();
       if (stat == 0)
 	{
@@ -503,9 +528,19 @@ xyzModem_stream_read (char *buf, int size, int *err)
 	  retries = xyzModem_MAX_RETRIES;
 	  while (retries-- > 0)
 	    {
+	      if (xyz.first_xmodem_packet && xyz.timeout &&
+		  get_timer(xyz.initial_time) > xyz.timeout)
+		{
+		  *err = xyzModem_timeout;
+		  xyz.len = -1;
+		  return total;
+		}
+
 	      stat = xyzModem_get_hdr ();
 	      if (stat == 0)
 		{
+		  if (xyz.mode == xyzModem_xmodem && xyz.first_xmodem_packet)
+		    xyz.first_xmodem_packet = false;
 		  if (xyz.blk == xyz.next_blk)
 		    {
 		      xyz.tx_ack = true;
@@ -583,7 +618,7 @@ xyzModem_stream_read (char *buf, int size, int *err)
 	      xyz.total_retries++;
 	      ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
 	    }
-	  if (stat < 0)
+	  if (stat < 0 && (!xyz.first_xmodem_packet || stat != xyzModem_timeout))
 	    {
 	      *err = stat;
 	      xyz.len = -1;
-- 
2.20.1