[PATCH v5 18/20] net-lwip: add TFTP_BLOCKSIZE

Jerome Forissier
2024-07-25T13:01:31Z

Add support for setting the TFTP block size. The default value (1468)
is fine for Ethernet and allows a better throughput than the TFTP
default (512), if the server supports the blksize option of course.

I tested this change with qemu_arm64_lwip_defconfig. The throughput is
now 875 KiB/s vs. 313 KiB/s before. That is still a low number, but I
think we can't expect more without implementing the windowsize option.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
---
net/Kconfig | 20 ++++++++++----------
net/lwip/tftp.c | 2 ++
2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/net/Kconfig b/net/Kconfig
index 952690d677d..7e5406bb923 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -69,16 +69,6 @@ config SYS_FAULT_ECHO_LINK_DOWN
this option is active, then CONFIG_SYS_FAULT_MII_ADDR also needs to
be configured.

-config TFTP_BLOCKSIZE
- int "TFTP block size"
- default 1468
- help
- Default TFTP block size.
- The MTU is typically 1500 for ethernet, so a TFTP block of
- 1468 (MTU minus eth.hdrs) provides a good throughput with
- almost-MTU block sizes.
- You can also activate CONFIG_IP_DEFRAG to set a larger block.
-
config TFTP_PORT
bool "Set TFTP UDP source/destination ports via the environment"
help
@@ -263,4 +253,14 @@ config SYS_RX_ETH_BUFFER
since all buffers can be full shortly after enabling the interface on
high Ethernet traffic.

+config TFTP_BLOCKSIZE
+ int "TFTP block size"
+ default 1468
+ help
+ Default TFTP block size.
+ The MTU is typically 1500 for ethernet, so a TFTP block of
+ 1468 (MTU minus eth.hdrs) provides a good throughput with
+ almost-MTU block sizes.
+ You can also activate CONFIG_IP_DEFRAG to set a larger block.
+
endif # if NET || NET_LWIP
diff --git a/net/lwip/tftp.c b/net/lwip/tftp.c
index 78de0bd0dba..1fe948c84ec 100644
--- a/net/lwip/tftp.c
+++ b/net/lwip/tftp.c
@@ -136,6 +136,8 @@ static int tftp_loop(struct udevice *udev, ulong addr, char *fname,
if (!(err == ERR_OK || err == ERR_USE))
log_err("tftp_init_client err: %d\n", err);

+ tftp_client_set_blksize(CONFIG_TFTP_BLOCKSIZE);
+
ctx.start_time = get_timer(0);
err = tftp_get(&ctx, &srvip, srvport, fname, TFTP_MODE_OCTET);
/* might return different errors, like routing problems */
--
2.40.1