Re: [PATCH V2 3/9] ARM: stm32: prepare stm32 family to welcome armv7 architecture

[Ludovic BARRE]

hi Arnd

just a ping, on Alex's proposal (below) about armv7m_restart
(Currently "restart" is not functional on stm32 MCU).

BR
Ludo
On 12/19/2017 03:38 PM, Alexandre Torgue wrote:
> On 12/18/2017 09:24 PM, Arnd Bergmann wrote:
> > On Mon, Dec 18, 2017 at 4:17 PM, Ludovic Barre <ludovic.Barre@xxxxxx> 
> > wrote:
> > > From: Ludovic Barre <ludovic.barre@xxxxxx>
> > >
> > > This patch prepares the STM32 machine for the integration of Cortex-A
> > > based microprocessor (MPU), on top of the existing Cortex-M
> > > microcontroller family (MCU). Since both MCUs and MPUs are sharing
> > > common hardware blocks we can keep using ARCH_STM32 flag for most of
> > > them. If a hardware block is specific to one family we can use either
> > > ARM_SINGLE_ARMV7M or ARCH_MULTI_V7 flag.
> > >
> > > Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> >
> > Looks good overall. Two more small comments:
> >
> >
> > > +if ARCH_STM32
> > > +
> > > Â config MACH_STM32F429
> > > -ÂÂÂÂÂÂ bool "STMicrolectronics STM32F429"
> > > -ÂÂÂÂÂÂ depends on ARCH_STM32
> > > +ÂÂÂÂÂÂ bool "STMicroelectronics STM32F429"
> > > +ÂÂÂÂÂÂ depends on ARM_SINGLE_ARMV7M
> > > ÂÂÂÂÂÂÂÂ default y
> >
> > Instead of the explicit dependency for each board, I'd leave the 
> > surrounding
> > 'if ARM_SINGLE_ARMV7M'. I think you had in v1.
> >
> > > diff --git a/arch/arm/mach-stm32/Makefile b/arch/arm/mach-stm32/Makefile
> > > index bd0b7b5..5940af1 100644
> > > --- a/arch/arm/mach-stm32/Makefile
> > > +++ b/arch/arm/mach-stm32/Makefile
> > > @@ -1 +1 @@
> > > -obj-y += board-dt.o
> > > +obj-$(CONFIG_ARM_SINGLE_ARMV7M) += board-mcu-dt.o
> > > diff --git a/arch/arm/mach-stm32/board-dt.c 
> > > b/arch/arm/mach-stm32/board-mcu-dt.c
> > > similarity index 100%
> > > rename from arch/arm/mach-stm32/board-dt.c
> > > rename to arch/arm/mach-stm32/board-mcu-dt.c
> >
> > Why the rename? I don't expect the new machines to have any notable
> > contents in a board file, if any at all, so just use one file for both.
> > I see the board-dt.c file refers to armv7m_restart, we can either put
> > that in an #ifdef, or find a way to make it the default for all armv7-m
> > platforms that don't provide any other restart method.
> Currently "restart" is not functional on stm32 MCU (at least for 
> stm32f746, I will check on others MCU). My fear is if Ludovic made some 
> patches to make "armv7m_restart" the default ".restart" function for all 
> armv7-m platform, he will not be able to test it on stm32 MCU (as it is 
> not currently working). I propose to do it in 2 steps:
>
> 1-Keep as you suggest only one board-dt.c file for both (MCU and MPU) 
> and remove ".restart" function.
>
> 2-Investigate and send patches around ".restart" for both in an other 
> series.

I resend

> regards
> Alex
>
>
> > ÂÂÂÂÂ Arnd