[U-Boot] [PATCH V2] i.MX28: Drop __naked function from spl_mem_init

[Stefano Babic]

On 16/03/2012 22:32, Marek Vasut wrote:
> Instead of compiling the function and using the result as a constant, simply use
> the constant.
> 
> NOTE: This patch works around bug:
> 
>   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52546
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Stefano Babic <sbabic at denx.de>
> Cc: Tom Rini <trini at ti.com>
> ---

Hi Marek,

>  arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c |   10 +++-------
>  1 files changed, 3 insertions(+), 7 deletions(-)
> 
> V2: Add comment that this works around bug in GCC
> 
> diff --git a/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c b/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c
> index 43a90ff..911bbef 100644
> --- a/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c
> +++ b/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c
> @@ -173,22 +173,18 @@ void mx28_mem_setup_vddd(void)
>  		&power_regs->hw_power_vdddctrl);
>  }
>  
> -void data_abort_memdetect_handler(void) __attribute__((naked));
> -void data_abort_memdetect_handler(void)
> -{
> -	asm volatile("subs pc, r14, #4");
> -}
> -
>  void mx28_mem_get_size(void)
>  {
>  	struct mx28_digctl_regs *digctl_regs =
>  		(struct mx28_digctl_regs *)MXS_DIGCTL_BASE;
>  	uint32_t sz, da;
>  	uint32_t *vt = (uint32_t *)0x20;
> +	/* The following is "subs pc, r14, #4", used as return from DABT. */
> +	const uint32_t data_abort_memdetect_handler = 0xe25ef004;

Are we maybe becoming warning addicted ? I know the reason for this (GCC
raises a warning "-fstack-usage not supported for this target"), you
have already asked the gcc people about this issue, and I do not have an
idea how to fix this warning in a different way as you did. This is a
sort of self-modifying code.

However, the original code is quite easy to understand - I cannot say
the same after the patch, we rely on the comment to understand something.

Should we really fix such as warnings even if we generate some obscured
code ? Wolfgang, what do you think about ?

Regards,
Stefano

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