[U-Boot] [PATCH v2 16/26] dm: tegra: net: Convert tegra boards to driver model for Ethernet

[Simon Glass]

Hi Stephen,

On 11 February 2016 at 16:21, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 12/13/2015 08:46 PM, Simon Glass wrote:
>>
>> Applied to u-boot-dm/next.
>
>
> I've found another strange problem, at least triggered/exposed by this
> patch:
>
> On at least either Dalmore or Jetson TK1, using USB Ethernet (hence with
> RTL8169 support disabled in include/configs/jetson-tk1.h[1]), I find that if
> I execute the following commands at or after this patch, then the system
> reboots during DHCP operation:
>
> save mmc 1:1 $loadaddr /dfu_dummy.bin 0x3c0
> usb start
> setenv autoload no
> dhcp
>
> yields:
>
> ====================
> Tegra124 (Jetson TK1) # dhcp
> Waiting for Ethernet connection... done.
> BOOTP broadcast 1
> DHCP client bound to address 10.20.204.50 (1 ms)
> data abort
> pc : [<fff6f1d4>]          lr : [<fff59fd0>]
> reloc pc : [<801291d4>]    lr : [<80113fd0>]
> sp : fda4e720  ip : 450088df     fp : fda60048
> r10: fffa4fe3  r9 : fda53ee0     r8 : 00000000
> r7 : 00000000  r6 : 00000000     r5 : 00000000  r4 : fda60048
> r3 : 00000383  r2 : 00000000     r1 : 00000000  r0 : e10f354b
> Flags: NzCv  IRQs off  FIQs off  Mode SVC_32
> Resetting CPU ...
>
> resetting ...
> ====================
>
> However, if I execute those commands at the commit before this patch, then
> everything is OK.
>
> The "save" command is definitely required to trigger this issue. The
> partition being saved to is a 1024MiB ext4 filesystem that's almost empty.
> If I omit the save, or save to a 1024MiB FAT filesystem instead, there's no
> error. This leads me to suspect some kind of memory corruption rather than a
> direct problem with this patch. Due to ext4 interaction, also CCing Łukasz
> in case he has any quick ideas.
>
> I'll go track down the PC where the error occurs and try and add some debug
> spew etc. to see what's up. Any other ideas appreciated though.
>
> (This is the problem with writing test systems; they show up bugs!)
>
>
>
> [1] i.e. I have this change made locally so that no PCIe Ethernet device
> exists, which causes the USB Ethernet to be used by default:
>
> diff --git a/include/configs/jetson-tk1.h b/include/configs/jetson-tk1.h
> index 23b2e436167c..af26b055b70b 100644
> --- a/include/configs/jetson-tk1.h
> +++ b/include/configs/jetson-tk1.h
> @@ -62,7 +62,6 @@
>  #define CONFIG_CMD_PCI
>
>  /* PCI networking support */
> -#define CONFIG_RTL8169
>
>  /* General networking support */
>  #define CONFIG_CMD_DHCP
>

I have seen some odd things on Seaboard which is a bit more forgiving
with RAM at 0 (although not Jetson-TK1, right?). It can sometimes mask
an issue where a driver has not auto-allocated space, but the driver
is using it anyway (i.e. using a NULL pointer as its private data).

I can't see anything wrong from inspection. The per-child data (struct
usb_device) appears to be cache-aligned as expected.

Which USB Ethernet driver are you using?

It would be great to fix this.

Regards,
Simon