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    SubjectRe: [PATCH 2/2] ARM: OMAP: hwmod: revise deassert sequence
    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@linaro.org>
    > ---
    > 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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