[PATCH 0/5] arm: mvebu: turris_omnia: Fix hangup in debug UART

[Pali Rohár]

On Monday 16 May 2022 16:52:06 Stefan Roese wrote:
> Hi Pali,
> 
> On 06.05.22 11:05, Pali Rohár wrote:
> > If proper U-Boot on Turris Omnia tries to print something on debug UART
> > then CPU hangs. Reason is that debug UART in proper U-Boot for Turris
> > Omnia has incorrect configuration of base register. Base register is
> > different in SPL and also in different stages of proper U-Boot.
> > 
> > Fix all these issues. Introduce new arch_very_early_init() ARM function
> > which will be called at very early stage prior initialization of debug
> > UART. Move code which moves internal mvebu registers to this function.
> > And split configuration of DEBUG_UART_BASE into SPL and proper U-Boot
> > to allow setting different values which matches current HW status.
> > 
> > With all these changes, it is possible call "printf" function in
> > Turris Omnia's board_early_init_f() function in both SPL and proper
> > U-Boot.
> > 
> > Pali Rohár (5):
> >    arm: Add new config option ARCH_VERY_EARLY_INIT
> >    arm: mvebu: Move internal registers in arch_very_early_init() function
> >    serial: Add new config option SPL_DEBUG_UART_BASE
> >    serial: ns16550: Add support for SPL_DEBUG_UART_BASE
> >    arm: mvebu: turris_omnia: Fix DEBUG_UART_BASE
> > 
> >   arch/arm/Kconfig               |  6 ++++++
> >   arch/arm/lib/crt0.S            |  5 +++++
> >   arch/arm/mach-mvebu/Kconfig    |  1 +
> >   arch/arm/mach-mvebu/Makefile   |  1 +
> >   arch/arm/mach-mvebu/cpu.c      | 31 -------------------------------
> >   arch/arm/mach-mvebu/lowlevel.S | 27 +++++++++++++++++++++++++++
> >   configs/turris_omnia_defconfig |  3 ++-
> >   drivers/serial/Kconfig         |  7 +++++++
> >   drivers/serial/ns16550.c       |  4 ++--
> >   9 files changed, 51 insertions(+), 34 deletions(-)
> >   create mode 100644 arch/arm/mach-mvebu/lowlevel.S
> 
> This patchset seems to introduce problems on some non-MVEBU platforms
> like x86, chromebook_coral_defconfig:
> 
> drivers/serial/ns16550.c: In function ‘_debug_uart_init’:
> ././include/linux/kconfig.h:51:32: error: ‘CONFIG_TPL_DEBUG_UART_BASE’
> undeclared (first use in this function); did you mean
> ‘CONFIG_SPL_DEBUG_UART_BASE’?
>    51 | #define __config_val(pfx, cfg) CONFIG_ ## pfx ## cfg
>       |                                ^~~~~~~
> ././include/linux/kconfig.h:50:32: note: in expansion of macro
> ‘__config_val’
>    50 | #define  _config_val(pfx, cfg) __config_val(pfx, cfg)
>       |                                ^~~~~~~~~~~~
> ././include/linux/kconfig.h:49:33: note: in expansion of macro ‘_config_val’
>    49 | #define   config_val(cfg)       _config_val(_CONFIG_PREFIX, cfg)
>       |                                 ^~~~~~~~~~~
> ././include/linux/kconfig.h:61:29: note: in expansion of macro ‘config_val’
>    61 | #define CONFIG_VAL(option)  config_val(option)
>       |                             ^~~~~~~~~~
> drivers/serial/ns16550.c:328:54: note: in expansion of macro ‘CONFIG_VAL’
>   328 |         struct ns16550 *com_port = (struct ns16550
> *)CONFIG_VAL(DEBUG_UART_BASE);
>       |                                                      ^~~~~~~~~~
> ././include/linux/kconfig.h:51:32: note: each undeclared identifier is
> reported only once for each function it appears in
>    51 | #define __config_val(pfx, cfg) CONFIG_ ## pfx ## cfg
>       |                                ^~~~~~~
> ././include/linux/kconfig.h:50:32: note: in expansion of macro
> ‘__config_val’
>    50 | #define  _config_val(pfx, cfg) __config_val(pfx, cfg)
>       |                                ^~~~~~~~~~~~
> ././include/linux/kconfig.h:49:33: note: in expansion of macro ‘_config_val’
>    49 | #define   config_val(cfg)       _config_val(_CONFIG_PREFIX, cfg)
>       |                                 ^~~~~~~~~~~
> ././include/linux/kconfig.h:61:29: note: in expansion of macro ‘config_val’
>    61 | #define CONFIG_VAL(option)  config_val(option)
>       |                             ^~~~~~~~~~
> drivers/serial/ns16550.c:328:54: note: in expansion of macro ‘CONFIG_VAL’
>   328 |         struct ns16550 *com_port = (struct ns16550
> *)CONFIG_VAL(DEBUG_UART_BASE);
>       |                                                      ^~~~~~~~~~
> drivers/serial/ns16550.c: In function ‘_debug_uart_putc’:
> ././include/linux/kconfig.h:51:32: error: ‘CONFIG_TPL_DEBUG_UART_BASE’
> undeclared (first use in this function); did you mean
> ‘CONFIG_SPL_DEBUG_UART_BASE’?
>    51 | #define __config_val(pfx, cfg) CONFIG_ ## pfx ## cfg
>       |                                ^~~~~~~
> ././include/linux/kconfig.h:50:32: note: in expansion of macro
> ‘__config_val’
>    50 | #define  _config_val(pfx, cfg) __config_val(pfx, cfg)
>       |                                ^~~~~~~~~~~~
> ././include/linux/kconfig.h:49:33: note: in expansion of macro ‘_config_val’
>    49 | #define   config_val(cfg)       _config_val(_CONFIG_PREFIX, cfg)
>       |                                 ^~~~~~~~~~~
> ././include/linux/kconfig.h:61:29: note: in expansion of macro ‘config_val’
>    61 | #define CONFIG_VAL(option)  config_val(option)
>       |                             ^~~~~~~~~~
> drivers/serial/ns16550.c:363:54: note: in expansion of macro ‘CONFIG_VAL’
>   363 |         struct ns16550 *com_port = (struct ns16550
> *)CONFIG_VAL(DEBUG_UART_BASE);
>       |                                                      ^~~~~~~~~~
> make[3]: *** [scripts/Makefile.build:258: tpl/drivers/serial/ns16550.o]
> Error 1
> 
> Could you please take a look?
> 
> Thanks,
> Stefan

I totally forgot for TPL. Fixed in additional patch "serial: Add new
config option TPL_DEBUG_UART_BASE" which I sent recently.

With this patch chromebook_coral_defconfig with x86 compiler builds
fine.