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

[Marek Vasut <marex@denx.de>]

Dear 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@denx.de>
> > Cc: Stefano Babic <sbabic@denx.de>
> > Cc: Tom Rini <trini@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.

I have an idea -- patch GCC >:-) Which is exactly what I'm gonna do when I have 
time ^H^H^H^H^H^H^H^H^H completely loose it :)

> 
> 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.

Sadly, yes.

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

It generates warnings in our jenkins CI.

> 
> Regards,
> Stefano

Best regards,
Marek Vasut