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Subject: Re: [Regression 5.6-rc1][Bisected b6231ea2b3c6] Powerpc 8xx doesn't
 boot anymore
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Li Yang <leoyang.li@nxp.com>, Qiang Zhao <qiang.zhao@nxp.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Scott Wood <oss@buserror.net>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-arm-kernel@lists.infradead.org
References: <0d45fa64-51ee-0052-cb34-58c770c5b3ce@c-s.fr>
 <aee10440-c244-7c93-d3bb-fd29d8a83be4@c-s.fr>
From:   Rasmus Villemoes <linux@rasmusvillemoes.dk>
Message-ID: <59487f8a-fd2e-703d-d954-d263f756a3a0@rasmusvillemoes.dk>
Date:   Thu, 13 Feb 2020 10:37:44 +0100
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On 12/02/2020 15.50, Christophe Leroy wrote:
> 
> 
> On 02/12/2020 02:24 PM, Christophe Leroy wrote:

>> In your commit text you explain that cpm_muram_init() is called via
>> subsys_initcall. But console init is done before that, so it cannot work.
>>
>> Do you have a fix for that ?
>>
> 
> The following patch allows powerpc 8xx to boot again. Don't know if
> that's the good place and way to do the fix though.
> 
> ---
> diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> index 4cabded8390b..341d682ec6eb 100644
> --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> @@ -1351,6 +1351,7 @@ static int __init cpm_uart_console_setup(struct
> console *co, char *options)
>          clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
>      }
> 
> +    cpm_muram_init();
>      ret = cpm_uart_allocbuf(pinfo, 1);
> 
>      if (ret)

Hmm, that seems to be a somewhat random place, making it hard to see
that it is indeed early enough. Would it work to put it inside the
console_initcall that registers the cpm console? I.e.

static int __init cpm_uart_console_init(void)
{
+       cpm_muram_init();
        register_console(&cpm_scc_uart_console);
        return 0;
}

console_initcall(cpm_uart_console_init);

Rasmus