Hi Ramon, On Sun, Apr 03, 2022 at 02:17:26AM +0300, Ramon Fried wrote: > On Thu, Mar 31, 2022 at 8:43 AM Ramon Fried wrote: > > On Tue, Mar 29, 2022 at 11:28 PM Laurent Pinchart wrote: > > > > > > Hello, > > > > > > I've banged my head a few days ago trying to debug an issue with a TFTP > > > transfer hanging in the middle. > > > > > > I'm testing U-Boot 2022-rc5 on a Toradex Verdin i.MX8MP module (using > > > the verdin-imx8mp defconfig). My local network MTU is 1500 bytes, and > > > the board uses the EQoS ethernet controller. > > > > > > The problem started occurring after rebuilding a kernel image. U-Boot > > > started transferring the image, and stopped in the middle, eventually > > > timing out. Capture network traffic showed that U-Boot was continuously > > > asking for retransmit of the same block, and eventually timed out. > > > > > > U-Boot is configured with a default TFTP block size of 4096 bytes, which > > > results in the TFTP blocks being sent in one UDP packet split in three > > > IP packets. U-Boot is configured with IP fragmentation supprot enabled. > > > This works fine for all TFTP blocks until a paticular one in the middle > > > of the kernel image. > > > > > > I've narrowed it down to a file of 1472 that can't be transferred at > > > all (I have attached the binary to this e-mail). Changing the value of > > > any of the last two bytes of the file allows transferring it correctly, > > > so I suspect a CRC issue, likely related to IP fragmentation. Lowering > > > the TFTP block size to avoid fragmentation works around the problem. > > > > > > Arguably a TFTP block size of 4096 bytes should probably not be used > > > with a 1500 bytes MTU network, but I thought it would be useful to fix > > > the issue nonetheless. > > > > > > I can test patches. > > > > > Interesting. > > I will try to reproduce. > > Thanks for reporting. > > Hi. > I couldn't reproduce the issue with the file you provided. > I used sandbox64, and changed the TFTP BLOCK size to 4096. > I managed to TFTP the file successfully. > > => setenv autoload no > => setenv ethrotate no > => setenv ethact eth0 > => setenv ipaddr > => setenv serverip 172.23.1.137 > => env set ipaddr 172.23.1.100 > => tftpboot 0x100000 test.bin > Using host_eno1 device > TFTP from server 172.23.1.137; our IP address is 172.23.1.100 > Filename 'test.bin'. > Load address: 0x100000 > Loading: # > 718.8 KiB/s > done > Bytes transferred = 1472 (5c0 hex) > =>
Hmmmm... I wonder if it could be specific to the EQoS ethernet controller in the i.MX8, maybe caused by issues in hardware CRC calculation ? I don't have any other board I can use for testing this at the moment as I'm travelling. > Can you perhaps send me a network PCAP of your device failing to > digest the file ? I'll try to do that tomorrow. -- Regards, Laurent Pinchart
