Hi Omar,
On 08/22/2012 07:42 AM, Omar Ramirez Luna wrote:
> For a reset sequence to complete cleanly, a module needs its
> associated clocks to be enabled, otherwise the timeout check
> in prcm code can print a false failure (failed to hardreset)
> that occurs because the clocks aren't powered ON and the status
> bit checked can't transition without them.
>
> Signed-off-by: Omar Ramirez Luna <omar.luna@xxxxxxxxxx>
> ---
> arch/arm/mach-omap2/omap_hwmod.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index eaedc33..b65e021 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -1509,6 +1509,7 @@ static int _deassert_hardreset(struct omap_hwmod *oh, const char *name)
> {
> struct omap_hwmod_rst_info ohri;
> int ret = -EINVAL;
> + int hwsup = 0;
>
> if (!oh)
> return -EINVAL;
> @@ -1520,10 +1521,46 @@ static int _deassert_hardreset(struct omap_hwmod *oh, const char *name)
> if (IS_ERR_VALUE(ret))
> return ret;
>
> + if (oh->clkdm) {
> + /*
> + * A clockdomain must be in SW_SUP otherwise reset
> + * might not be completed. The clockdomain can be set
> + * in HW_AUTO only when the module become ready.
> + */
> + hwsup = clkdm_in_hwsup(oh->clkdm);
> + ret = clkdm_hwmod_enable(oh->clkdm, oh);
> + if (ret) {>
> + WARN(1, "omap_hwmod: %s: could not enable clockdomain %s: %d\n",
> + oh->name, oh->clkdm->name, ret);
> + return ret;
> + }
> + }
> +
> + _enable_clocks(oh);
> + if (soc_ops.enable_module)
> + soc_ops.enable_module(oh);
> +
> ret = soc_ops.deassert_hardreset(oh, &ohri);
> +
> + if (soc_ops.disable_module)
> + soc_ops.disable_module(oh);
> + _disable_clocks(oh);
> +
> if (ret == -EBUSY)
> pr_warning("omap_hwmod: %s: failed to hardreset\n", oh->name);
>
> + if (!ret) {
> + /*
> + * Set the clockdomain to HW_AUTO, assuming that the
> + * previous state was HW_AUTO.
> + */
> + if (oh->clkdm && hwsup)
> + clkdm_allow_idle(oh->clkdm);
> + } else {
> + if (oh->clkdm)
> + clkdm_hwmod_disable(oh->clkdm, oh);
> + }
> +
> return ret;
> }
>
The sequence is good, I'm just a little bit concern about the
duplication of code compared to _enable sequence.
That being said, this is the consequence of removing the hardreset
sequence outside of the main _enable/_shutdown sequence.
So I'm not sure I have any better way of doing that :-(
Regards,
Benoit
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