On 07/15/2013 05:12 PM, Marek Vasut wrote:
Hi Hector,

Hi Marek,

On 07/15/2013 02:30 PM, Marek Vasut wrote:
Dear Hector Palacios,

Hi Marek,

On 07/12/2013 06:48 PM, Marek Vasut wrote:
   [...]

but I found something:
It is very strange that the timeouts appear always after transferring
between 20 and 24 MiB. So I thought maybe it was not an issue with the
size of the file or the number of packets received, but instead a
timed issue (an issue that happens after some period of time). I
checked, and in fact the timeouts occur exactly 10 seconds after
running the tftp command. I verified that this is what is happening
by adding a udelay(100000) at fec_send(). In this case, the timeout
also occurs after 10 seconds, but due to the delay, I have
transferred only a few Kbytes.

Holy moly!

I tried to change different timeout related constants at tftp.c but
still the issue happens after 10s.
It's like if, after these 10 seconds, the PHY lost the link or
something. Really odd. Does it tell you anything?

LAN8720 phy, right? Try implementing something like [1], by clearing
the EDPWRDOWN bit , the PHY will never enter low-power mode. It's just
a simple PHY register RMW which you can stick somewhere into the PHY
net/phy/smsc.c code.

[1]
https://kernel.googlesource.com/pub/scm/linux/kernel/git/djbw/dmaengine
/+ /b629820d18fa65cc598390e4b9712fd5f83ee693%5E!/#F0

No, my PHY is a Micrel KSZ8031RNLI.

The hint about the PHY possibly going to power down mode is interesting
but I checked the PHY registers and EDPD mode (Energy Detect Power
Down) is off, at least before running the tftp command. Power Down mode
is off too, so unless these are somehow enabled during the TFTP
process, this is not what's happening.

OK, makes sense.

The sniffer shows that the TFTP server simply stops sending data
packets. I can see however the target sending several times the ACK
packet to the last received data packet. This would point to the TFTP
server (as Albert suggested), but the fact is the problem occurs with
different TFTP servers (I tried three different servers) and it does
not happen with an old v2009 U-Boot using the same target.

Can you try running "dcache off" command before running the TFTP
transfer? Does it still behave like this?

You might need to define #define CONFIG_CMD_CACHE for this to work.

Sourcery!
It's not that it works with dcache off, I found something even more
strange: The way I reproduce this issue is by setting the 'bootcmd' to
'dboot ${loadaddr} file100M'. When you set the 'bootcmd' like this:

        setenv bootcmd tftp ${loadaddr} file100M

this eventually expands to

        bootcmd=tftp 0x42000000 file100M

So this is the command that runs automatically after the bootdelay.
I just discovered that if instead of letting the auto boot run, I press a
key to stop the auto boot and run the command by hand (either running
'boot' or typing the command 'tftp 0x42000000 file100M'), the tftp
transfer works perfectly.
On the other hand, if I do the same but use the environment variable
${loadaddr}, i.e. 'tftp ${loadaddr} file100M'. It will stop after 10
seconds.

Count it be your hardware needs some more delay to stabilize?

It's not a problem of running the command later. If I run the command later, manually, but use ${loadaddr} instead of the hardcoded value 0x42000000, then it will fail. It's like if accessing the environment for grabbing the value of ${loadaddr} or for grabbing the value of ${bootcmd}, made the problem appear, while if I run a manual command that does not require accesing the environment, it works.

And to make things funnier I just reproduced this issue on the MX28EVK
using the imx U-Boot custodian tree at commit
a3f170cdbf7ae0bd24c94c2f46725699bbd69f05. That discards being a platform
issue.

It still might be a PHY issue, no?

I guess it might, but the MX28EVK uses a different PHY. An SMSC, I believe.

@Fabio: could you manually run the command 'tftp ${loadaddr} file100M'

I guess that'd be a 100MB file?

Yes. The size is not that important as far as it takes more than 10 seconds to download. The keypoint here is using the environment variable, rather than an hex value.

Best regards,
--
Hector Palacios
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