Data abort when starting DFU on SAMA5D2

[Alexis Lothoré]

Hello Zixun, Eugen,

On 8/2/23 09:38, admin LI wrote:
> Hi  Alexis,
> 
> I've tried to USB gardet under u-boot without success (linux is ok).
> 
> I've contacted Microchip support (No.01275010) and from them:
> "we confirmed with the internal team that USB is not fully functional with
> u-boot so for any query related to working of USB in u-boot we request you to
> create a NASCAR."

Thanks for the feedback and the status confirmation. I fell back with sam-ba for
the moment

Kind regards,

> 
> Regards,
> Zixun
> 
> On Wed, Aug 2, 2023 at 9:11 AM Eugen Hristev <eugen.hristev at collabora.com
> <mailto:eugen.hristev at collabora.com>> wrote:
> 
>     Hi Alexis,
> 
>     On 8/1/23 10:09, Alexis Lothoré wrote:
>     > Hi,
>     > I am currently using an ATSAMA5D27-WLSOM1-EK1. This boards embeds an
>     > ATSAMA5D27-WLSOM1, which in turns holds an ATSAMA5D27 and a 8MB QSPI flash. I
>     > have been wanting to program u-boot in the QSPI flash thanks to DFU, since the
>     > board is able to boot from QSPI and is supported in uboot. To do so, I have
>     > executed the following steps:
>     > - check out recent uboot version (2023.07.02, but issed described below is
>     > observed on master too)
>     > - load sama5d27_wlsom1_ek_qspiflash_defconfig
>     > - tune the configuration to enable DFU:
>     >    - CONFIG_CMD_DFU=y
>     >    - CONFIG_DFU_SF=y
>     >    - CONFIG_USB_GADGET_DOWNLOAD=y
>     > - build uboot, upload and run it onto external ram thanks to snagrecover
>     ([1]).
>     >    - running "bdinfo" shows that board is properly defined/recognized
>     >    - "sf probe" properly detects the qspi flash chip
>     > - in u-boot console, configure dfu:
>     >    - setenv dfu_alt_info uboot raw 0 0x80000
>     > - start DFU:
>     >    - dfu 0 sf 2:0
>     >
>     > Unfortunately, this step systematically and immediately leads to a data abort
>     > with the following log:
>     >
>     > => dfu 0 sf 2:0
>     > data abort
>     > pc : [<2fda9ee0>]        lr : [<2fd8dc08>]
>     > reloc pc : [<26f3fee0>]lr : [<26f23c08>]
>     > sp : 2f963fe8  ip : 2f9829cc   fp : 00000000
>     > r10: 2fde1cd9  r9 : 2f969e80   r8 : 2fdfc304
>     > r7 : 00000000  r6 : 00000000   r5 : 2fdf3034  r4 : 2f982948
>     > r3 : 0a299cfc  r2 : ffffffec   r1 : 00000000  r0 : 00000000
>     > Flags: nzCv  IRQs off  FIQs off  Mode SVC_32
>     > Code: e5843058 e5950004 e3a01000 e5903008 (e5933008)
>     > Resetting CPU ...
>     >
>     > resetting ...
>     > System reset not supported on this platform
>     > ### ERROR ### Please RESET the board ###
>     >
>     > A quick translation with addr2line shows that the data abort occurs in
>     > include/linux/usb/gagdet.h, in usb_ep_alloc_request, likely because of ep
>     being
>     > NULL, which seems confirmed by adding some custom logs in both
>     > usb_ep_alloc_request and its caller (composite_bind). Before digging further,
>     > does anyone have successfully used DFU on SAMA5D2 boards (and if so, am I
>     > missing something in the configuration) ? Or does this data abort show
>     that some
>     > support is still missing to make it work for SAMA5D2 ?
> 
>     I believe this is related to the gadget more than DFU itself.
>     Zixun LI (in CC) has attempted gadget on this platform at some point.
> 
>     Mihai (also in CC) has did some tests with USB on this platform as well.
>     Cristian has more knowledge of the USB implementation on sama5d2.
> 
>     Eugen
> 
>     >
>     > Kind regards,
>     > Alexis
>     >
>     > [1] https://github.com/bootlin/snagboot <https://github.com/bootlin/snagboot>
> 

-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com