Re: beaglebone black boot failure Linux v5.15.rc1

Suman Anna
2021-09-21T16:07:27Z

Hi Matti, Tony,

On 9/21/21 2:47 AM, Tony Lindgren wrote:
> * Matti Vaittinen <mazziesaccount@gmail.com> [210920 08:23]:
>> Finally, adding the udelay(100); (as Tony suggested) at the end of the
>> omap_reset_deassert() did make the oops go away even when pruss_tm was
>> enabled. I don't know what would be a proper fix though.

I have been able to boot v5.15-rc1 just fine on my BBB without any additional
changes [1].

May I ask what is your BBB board version? My board is rev.A5C.

I vaguely remember from all those years ago when I first enabled PRUSS on AM335x
that some earlier BBB versions had some issues around PRUSS.

regards
Suman

[1] https://marc.info/?l=linux-omap&m=163223991005545&w=2

>
> The following patch works for me on bbb with the following test script:
>
> #!/bin/sh
>
> module="4a326000.target-module"
> driver="/sys/bus/platform/drivers/ti-sysc"
>
> while true; do
> echo ${module} > ${driver}/bind
> echo ${module} > ${driver}/unbind
> done
>
> It also allows leaving out the udelay for dra7 iva reset. Care to try
> this and see if it helps?
>
> Regards,
>
> Tony
>
> 8< -----------------
> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
> --- a/drivers/soc/ti/omap_prm.c
> +++ b/drivers/soc/ti/omap_prm.c
> @@ -825,26 +825,29 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
> writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl);
> spin_unlock_irqrestore(&reset->lock, flags);
>
> - if (!has_rstst)
> - goto exit;
> -
> - /* wait for the status to be set */
> - ret = readl_relaxed_poll_timeout_atomic(reset->prm->base +
> + if (has_rstst) {
> + /* wait for the status to be set */
> + ret = readl_relaxed_poll_timeout_atomic(reset->prm->base +
> reset->prm->data->rstst,
> v, v & BIT(st_bit), 1,
> OMAP_RESET_MAX_WAIT);
> - if (ret)
> - pr_err("%s: timedout waiting for %s:%lu\n", __func__,
> - reset->prm->data->name, id);
> -
> -exit:
> - if (reset->clkdm) {
> - /* At least dra7 iva needs a delay before clkdm idle */
> - if (has_rstst)
> - udelay(1);
> - pdata->clkdm_allow_idle(reset->clkdm);
> + if (ret)
> + pr_err("%s: timedout waiting for %s:%lu\n", __func__,
> + reset->prm->data->name, id);
> + } else {
> + /* wait for the reset bit to cleaar */
> + ret = readl_relaxed_poll_timeout_atomic(reset->prm->base +
> + reset->prm->data->rstctrl,
> + v, !(v & BIT(id)), 1,
> + OMAP_RESET_MAX_WAIT);
> + if (ret)
> + pr_err("%s: timedout waiting for %s:%lu\n", __func__,
> + reset->prm->data->name, id);
> }
>
> + if (reset->clkdm)
> + pdata->clkdm_allow_idle(reset->clkdm);
> +
> return ret;
> }
>
>