[U-Boot] u-boot hangs after detecting DDR3 RAM and Flash.

[prakash bedge]

Hi Stefan,

Thanks.

Shall I need to add sleep() command in the interrupt_init or before it?

I am using Samsung M391B2873EH1-CH9 series 1 GB DDR3 and Denali controller
is being used for driving DDR3.

Regards,
Prakash

On Tue, May 4, 2010 at 8:04 PM, Stefan Roese <sr at denx.de> wrote:

> Hi Prakash,
>
> On Tuesday 04 May 2010 16:21:19 prakash bedge wrote:
> > I am facing an error while porting u-boot for my platform because if
> > exception error.
> >
> > After running the u-boot to detect the DDR and flash u-boot hangs after
> > showing the serial console output. In debugger I am seeing PC at
> 0x00000400
> > address which the exception handler vector address.
> >
> > But when I modify the below statement in the function int interrupt_init
> > (void) in u-boot\lib_ppc\interrupts.c, u-boot continues and I can see the
> > u-boot prompt and I am able to run all u-boot commands.
> >
> > int interrupt_init (void)
> > {
> >     int ret;
> >
> >     /* call cpu specific function from $(CPU)/interrupts.c */
> >     ret = interrupt_init_cpu (&decrementer_count);
> >
> >     if (ret)
> >         return ret;
> >
> >     set_dec (decrementer_count);
> >
> > ---    set_msr (get_msr () | MSR_EE);   //Removed this statement.
> > ++  set_msr (get_msr ());
>
> By not setting MSR_EE, you will not be able to receive external interrupts,
> or
> even worse, your timer will most likely not work. Try the "sleep" command.
>
> >     return (0);
> > }
> >
> > It seems that there is an exception error and because of this u-boot
> hangs.
> > But I didn't get any error condition till now.
> >
> > If someone has earlier experienced this kind of issue, please share.
>
> One thing I've noticed in other PPC4xx ports as well, is that DDR auto-
> calibration (with short memory tests) can lead to exceptions that need to
> be
> cleared after the DDR is fully configured. Example:
>
> arch/powerpc/cpu/ppc4xx/44x_spd_ddr2.c:
>
> phys_size_t initdram(int board_type)
> {
>        ...
>
>        /*
>         * Clear potential errors resulting from auto-calibration.
>         * If not done, then we could get an interrupt later on when
>         * exceptions are enabled.
>         */
>        set_mcsr(get_mcsr());
>
>
> Hard to tell, if you experience the same problem, since we have little
> information about your platform (which DDR3 core is used etc).
>
> Cheers,
> Stefan
>
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