TFTP: allow for adjustable retransmission timout
So far, TFTP negotiated a fixed retransmission timeout of 5 seconds.
In some cases (busy networks, slow TFTP servers) this caused very
slow transfers. A new environment variable "tftptimeout" allows to
set this timeout. Lowering this value may make downloads succeed
faster in networks with high packet loss rates or with unreliable
TFTP servers.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/README b/README
index 1158e24..940b507 100644
--- a/README
+++ b/README
@@ -3005,7 +3005,9 @@
working with an in-memory copy. In case the Flash area containing the
environment is erased by accident, a default environment is provided.
-Some configuration options can be set using Environment Variables:
+Some configuration options can be set using Environment Variables.
+
+List of environment variables (most likely not complete):
baudrate - see CONFIG_BAUDRATE
@@ -3117,7 +3119,7 @@
available network interfaces.
It just stays at the currently selected interface.
- netretry - When set to "no" each network operation will
+ netretry - When set to "no" each network operation will
either succeed or fail without retrying.
When set to "once" the network operation will
fail when all the available network interfaces
@@ -3133,7 +3135,18 @@
tftpdstport - If this is set, the value is used for TFTP's UDP
destination port instead of the Well Know Port 69.
- vlan - When set to a value < 4095 the traffic over
+ tftpblocksize - Block size to use for TFTP transfers; if not set,
+ we use the TFTP server's default block size
+
+ tftptimeout - Retransmission timeout for TFTP packets (in milli-
+ seconds, minimum value is 1000 = 1 second). Defines
+ when a packet is considered to be lost so it has to
+ be retransmitted. The default is 5000 = 5 seconds.
+ Lowering this value may make downloads succeed
+ faster in networks with high packet loss rates or
+ with unreliable TFTP servers.
+
+ vlan - When set to a value < 4095 the traffic over
Ethernet is encapsulated/received over 802.1q
VLAN tagged frames.