[PATCH 0/3] ARM: Fix reset in SPL if SYSRESET is not used

[Harald Seiler]

Hello,

On Wed, 2020-03-04 at 15:23 +0100, Harald Seiler wrote:
> Hello,
> 
> continuing on the discussion around Claudius' patch for fixing reset in SPL [1]
> we have taken a closer look at the issue.  To quickly summarize the situation:
> 
>     The original patch was to enable the generic ARM implementation of
>     `do_reset` if CONFIG_SYSRESET is not enabled in SPL.  This would break
>     compilation for some boards which define their own `do_reset` in
>     `board/*/spl.c`.
> 
>     To be more specific, the following 4 boards have this custom `do_reset`:
> 
>         - toradex/verdin-imx8mm
>         - freescale/imx8mn_evk
>         - freescale/imx8mm_evk
>         - freescale/imx8mp_evk
> 
> I hope we can all agree that `do_reset` is not at all meant to be implemented
> in board files.  From looking at the related code for imx8m, it feels like this
> was just a workaround hack to archieve the same thing which Claudius has fixed.
> So this patch series reverts the addition of `do_reset` implementations in
> imx8m board files and instead switches to using the proper fix provided by
> Claudius.
> 
> 
> Additionally, the custom do_reset implementations were passing an address
> (WDOG1_BASE_ADDR) to `reset_cpu()` instead of 0.  This is the only place in the
> entire U-Boot tree where this happens.  Instead, all other implementations
> simply ignore the parameter and 0 is passed by callers.  It looks a lot like
> this is a legacy left-over which makes me think that using it for a (hard-coded)
> watchdog address is not a good idea as it breaks convention with the rest of
> U-Boot.
> 
> [1]: https://patchwork.ozlabs.org/patch/1201959 
> 
> Claudius Heine (3):
>   ARM: reset: use do_reset in SPL/TPL if SYSRESET was not enabled for
>     them
>   imx: imx8m*: Remove do_reset from board files
>   imx: imx8m: Don't use the addr parameter of reset_cpu
> 
>  arch/arm/lib/Makefile             | 2 +-
>  arch/arm/mach-imx/imx8m/soc.c     | 5 +----
>  board/freescale/imx8mm_evk/spl.c  | 9 ---------
>  board/freescale/imx8mn_evk/spl.c  | 9 ---------
>  board/freescale/imx8mp_evk/spl.c  | 9 ---------
>  board/toradex/verdin-imx8mm/spl.c | 9 ---------
>  6 files changed, 2 insertions(+), 41 deletions(-)
> 

Quick question, what is the situation with this series?  Is there anything
which needs to be addressed?

Without it, CONFIG_SPL_USB_SDP_SUPPORT is broken on the imx6q hardware
I am working with and I guess the same issue might exist on many other
boards as well (The USB stack needs a do_reset() implementation in SPL).

Regards,
-- 
Harald