Re: [U-Boot] netconsole: USB Ethernet connection dropping with ping or tftpboot

On 02/05/2015 04:21 AM, Jörg Krause wrote:

On Di, 2015-02-03 at 22:44 +0100, Jörg Krause wrote:

...

I followed the instructions from Marek in 'M28 U-Boot Single-Wire Debug preview' to enable NetConsole: http://www.denx-cs.de/?q=blogm28singlewiredebug

I'm using mxsldr to flash the u-boot.sb image to RAM. This is the dmesg output from my host:

     [31048.492181] usb 3-13: new high-speed USB device number 24
     using xhci_hcd
     [31048.667617] cdc_ether 3-13:1.0 eth0: register 'cdc_ether' at
     usb-0000:00:14.0-13, CDC Ethernet Device, 00:19:b8:00:00:01
     [31048.669101] cdc_ether 3-13:1.0 enp0s20u13: renamed from eth0
     [31048.696758] cdc_ether 3-13:1.0 enp0s20u13: kevent 12 may have
     been dropped

I noticed the 'kevent 12 may have been dropped' message here.

Nevertheless, NetworkManager shows me a USB Ethernet connection and using './netconsole 10.0.0.2' I am able to communicate with the device, e.g. 'nand info' outputs correctly.

But if I use 'ping 10.0.0.1' or 'tftpboot u-boot.sb' the network connection drops. Both commands work fine if I switch back from netconsole to serial in-/output.

This is the output from dmesg: [31620.215354] usb 3-13: USB disconnect, device number 24 [31620.215422] cdc_ether 3-13:1.0 enp0s20u13: unregister 'cdc_ether' usb-0000:00:14.0-13, CDC Ethernet Device

Do I missed something?

I managed to get serial console and netconsole muxing to work, so I can see all the debug messages:

     Hit any key to stop autoboot:  5 using ci_udc, OUT ep- IN ep-
     STATUS ep-
     MAC 00:19:b8:00:00:02
     HOST MAC 00:19:b8:00:00:01
     high speed config #1: 2 mA, Ethernet Gadget, using CDC Ethernet
     USB network up!
      0
     => tftp u-boot.sb
     using ci_udc, OUT ep- IN ep- STATUS ep-
     timeout sending packets to usb ethernet

This reminded me about an issue I had some months ago: http://lists.denx.de/pipermail/u-boot/2014-July/182885.html

I enabled debug output in arch/arm/cpu/arm926ejs/cache.c and I get error: => tftp u-boot.sb using ci_udc, OUT ep- IN ep- STATUS ep- CACHE: Misaligned operation at range [43f7b010, 43f7b070]

I removed the flush_cache() call in cmd_net.c:netboot_common() as suggested by Marek in the thread. But the error message is still there.

Perhaps make flush_cache() a macro that also passes in the file/line number where it's called from, and print those out along with he "misaligned operation" error message?

(or find some other way to perform a stack dump from within that function).