Re: reset-loop on Odroid U2: cros-ec communications failure

[Joost van Zwieten]

On Fri, Jan 20, 2023 at 15:11, Simon Glass <s...@chromium.org> wrote:
Hi Joost,

On Fri, 20 Jan 2023 at 15:00, Joost van Zwieten <jo...@diskos.nl> 
wrote:



 On Fri, Jan 13, 2023 at 11:00, Simon Glass <s...@chromium.org> wrote:
 > Hi Joost,
 >
 > On Mon, 9 Jan 2023 at 06:31, Joost van Zwieten <jo...@diskos.nl>
 > wrote:
 >>
 >>  Dear maintainers,
 >>
 >>  U-Boot on my Odroid U2 fails to initialize as of commit
 >>  e44d7e73fe0d649693d8d0a110cd7632bc919273 (introduced after
 >> v2022.10). I
 >>  get the following output:
 >>
 >>      U-Boot 2022.10-00565-ge44d7e73fe-dirty (Jan 09 2023 - 
01:04:19
 >>  +0100)
 >>
 >>      CPU: Exynos4412 @ 1 GHz
 >>      Model: Odroid based on Exynos4412
 >>      Type: u3
 >>      DRAM: 2 GiB
 >>      Core: 101 devices, 12 uclasses, devicetree: separate
 >>      LDO20@VDDQ_EMMC_1.8V: set 1800000 uV; enabling
 >>      LDO22@VDDQ_EMMC_2.8V: set 2800000 uV; enabling
 >>      LDO21@TFLASH_2.8V: set 2800000 uV; enabling
 >>      MMC: SAMSUNG SDHCI: 2, EXYNOS DWMMC: 0
 >>      Loading Environment from MMC... *** Warning - bad CRC, using
 >>  default environment
 >>
 >>      cros-ec communications failure -96
 >>
 >>      Please reset with Power+Refresh
 >>
 >>      Cannot init cros-ec device
 >>      resetting ...
 >>
 >>  This repeats indefinitely. I'm building U-Boot using the default
 >> config
 >>  for board `odroid` and boot the Odroid from an SD card with 
firmware
 >>  (`bl1`, `bl2` and `tzsw`) from Hardkernel's clone of the u-boot
 >>  repository [1]. There are no peripherals connected apart from 
the SD
 >>  card and the serial console. Please let me know if you need more
 >>  information.
 >
 > board_late_init() is presumably enabled with 
CONFIG_BOARD_LATE_INIT
 > and the code in board/samsung/common/board.c is being called.
 >
 > -96 is -EPFNOSUPPORT which means that the CROS_EC uclass is 
missing.
 >
 > So either enable CROS_EC so you have the uclass, or disable
 > BOARD_LATE_INIT so it doesn't matter.
 >
 >>
 >>  Best, Joost
 >>
 >>  [1]:
 >>
 >> 
https://github.com/hardkernel/u-boot/tree/33e05ffb159141b640571e91470172d83a2a1273/sd_fuse
 >>
 >>
 >
 > Regards,
 > Simon

 Hi Simon,

 Thanks. Both solutions work. With `CROS_EC` enabled
 `uclass_first_device_err(UCLASS_CROS_EC, &dev)` returns `ENODEV`. 
Since
 `board_late_init()` seems to do legitimate work for this board
 (defining the `mmcbootdev` environment variable) I think enabling
 `CROS_EC` is the way to go. Should this be part of the defconfig for
 odroid? If so, I can send a patch.

Yes that seems OK to me.

Regards,
Simon

I've send a patch.

I'm still a bit puzzled by this problem, though. Is it correct that 
`uclass_first_device_err(UCLASS_CROS_EC, ...)` always returns 
`-EPFNOSUPPORT` when `CROS_EC` is disabled in the `.config`? If so, I 
don't see how U-Boot is going to function properly on any board that 
hits `board_late_init()` (board/samsung/common/board.c) with 
`BOARD_LATE_INIT=y` and `CROS_EC` undefined and perhaps the best 
solution is to run the CROS_EC related statements only if `CROS_EC` is 
actually defined. I'm not sure about the implications of this proposal 
further down the road, though.

Best, Joost