[PATCH v2 5/8] ARM: OMAP2+: hwmod: ensure that SYSCONFIG bits are reprogrammed after a reset

[Ramirez Luna, Omar]

Hi Paul,

2012/2/27 Paul Walmsley <paul at pwsan.com>:
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index db4ad41..aeb6f4c 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -1490,13 +1490,22 @@ static int _reset(struct omap_hwmod *oh)
>        pr_debug("omap_hwmod: %s: resetting\n", oh->name);
>
>        if (oh->class->reset)
> -               return oh->class->reset(oh);
> -
> -       if (!oh->rst_lines_cnt)
> -               return _ocp_softreset(oh);
> +               oh->class->reset(oh);
> +       else if (!oh->rst_lines_cnt)
> +               _ocp_softreset(oh);
> +       else
> +               for (i = 0; i < oh->rst_lines_cnt; i++)
> +                       _assert_hardreset(oh, oh->rst_lines[i].name);

If we reached here the reset lines will be asserted, and then the code
below touches sysc registers on a module under reset.

This would crash on _setup->_setup_reset->_reset.

Adding a 'return 0' I believe fixes the behavior, boots the board and
leaves the hwmod under reset.

-	else
+	} else {
 		for (i = 0; i < oh->rst_lines_cnt; i++)
 			_assert_hardreset(oh, oh->rst_lines[i].name);
+		return 0;
+	}

>
> -       for (i = 0; i < oh->rst_lines_cnt; i++)
> -               _assert_hardreset(oh, oh->rst_lines[i].name);
> +       /*
> +        * OCP_SYSCONFIG bits need to be reprogrammed after a
> +        * softreset.  The _enable() function should be split to avoid
> +        * the rewrite of the OCP_SYSCONFIG register.
> +        */
> +       if (oh->class->sysc) {
> +               _update_sysc_cache(oh);
> +               _enable_sysc(oh);
> +       }

Best Regards,

Omar