So far, TFTP negotiated a fixed retransmission timeout of 5 seconds. In some cases (busy networks, slow TFTP servers) this caused very slow transfers. Add 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 ---
I'm not sure if this change is really a good thing. It seems to help a lot in a test case I had here, but I'm not sure if the previous timeout settings that also depended on TftpRRQTimeoutMSecs were simply wrong (and not well tested - in myunderstanding they should affect only the connection timeout, but not the packet retransmission timeout), or if these are actually useful or needed in some configurations. So far, TftpRRQTimeoutMSecs is used in common/update.c only.
README | 19 ++++++++++++++++--- net/tftp.c | 22 +++++++++++++++++----- 2 files changed, 33 insertions(+), 8 deletions(-)
diff --git a/README b/README index 744f6bf..18ca11f 100644 --- a/README +++ b/README @@ -2989,7 +2989,9 @@ environment. As long as you don't save the environment you are 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
@@ -3101,7 +3103,7 @@ Some configuration options can be set using Environment Variables: 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 @@ -3117,7 +3119,18 @@ Some configuration options can be set using Environment Variables: 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.
diff --git a/net/tftp.c b/net/tftp.c index cc60a3b..f3ac54b 100644 --- a/net/tftp.c +++ b/net/tftp.c @@ -203,7 +203,7 @@ TftpSend (void) pkt += 5 /*strlen("octet")*/ + 1; strcpy ((char *)pkt, "timeout"); pkt += 7 /*strlen("timeout")*/ + 1; - sprintf((char *)pkt, "%lu", TIMEOUT / 1000); + sprintf((char *)pkt, "%lu", TftpTimeoutMSecs / 1000); debug("send option "timeout %s"\n", (char *)pkt); pkt += strlen((char *)pkt) + 1; #ifdef CONFIG_TFTP_TSIZE @@ -405,7 +405,6 @@ TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len) }
TftpLastBlock = TftpBlock; - TftpTimeoutMSecs = TIMEOUT; TftpTimeoutCountMax = TIMEOUT_COUNT; NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);
@@ -504,10 +503,24 @@ TftpStart (void) { char *ep; /* Environment pointer */
- /* Allow the user to choose tftpblocksize */ + /* + * Allow the user to choose TFTP blocksize and timeout. + * TFTP protocol has a minimal timeout of 1 second. + */ if ((ep = getenv("tftpblocksize")) != NULL) TftpBlkSizeOption = simple_strtol(ep, NULL, 10); - debug("tftp block size is %i\n", TftpBlkSizeOption); + + if ((ep = getenv("tftptimeout")) != NULL) + TftpTimeoutMSecs = simple_strtol(ep, NULL, 10); + + if (TftpTimeoutMSecs < 1000) { + printf("TFTP timeout (%ld ms) too low, " + "set minimum = 1000 ms\n); + TftpTimeoutMSecs = 1000; + } + + debug("TFTP blocksize = %i, timeout = %ld ms\n", + TftpBlkSizeOption, TftpTimeoutMSecs);
TftpServerIP = NetServerIP; if (BootFile[0] == '\0') { @@ -564,7 +577,6 @@ TftpStart (void)
puts ("Loading: *\b");
- TftpTimeoutMSecs = TftpRRQTimeoutMSecs; TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);