From: Teresa Gamez <T.Gamez@phytec.de>
To: Juergen Beisert <jbe@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH] phyCORE-i.MX27: Keep frequency multiplier enabled to be able to do a warmstart
Date: Wed, 25 May 2011 14:39:59 +0200 [thread overview]
Message-ID: <1306327199.22033.168.camel@lws-gamez> (raw)
In-Reply-To: <201011251752.42159.jbe@pengutronix.de>
Are there any reasons why this patch was not added to the barebox?
It works fine for us.
Teresa
Am Donnerstag, den 25.11.2010, 17:52 +0100 schrieb Juergen Beisert:
> commit 7d25a0552dd3a4b65412ae1cbf8f9ca8a88b5d27
> Author: Juergen Beisert <jbe@pengutronix.de>
> Date: Thu Nov 25 17:49:11 2010 +0100
>
> Keep frequency multiplier enabled to be able to do a warmstart
>
> The wachtdog's reset does only reset the ARM core, not the whole silicon.
> But the PLLs seems to do some strange things: It seems they switch back to
> the low frequency reference when the watchdog barks. But in the case the
> frequency multiplier is off (not used due to 26 MHz reference usage) the
> machine stops, because the PLLs are stopping due to the lack of a reference
> frequency. As the power on reset will set the FPM_EN bit again, a power cycle
> brings the machine back to life.
> By keeping the frequency multiplier enabled, also a warmstart triggered by the
> watchdog can restart the machine now.
>
> Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
>
> diff --git a/arch/arm/boards/pcm038/pll.h b/arch/arm/boards/pcm038/pll.h
> index 13a7989..15b94cf 100644
> --- a/arch/arm/boards/pcm038/pll.h
> +++ b/arch/arm/boards/pcm038/pll.h
> @@ -36,6 +36,7 @@
> CSCR_MCU_SEL | /* 26 MHz reference */ \
> CSCR_ARM_DIV(0) | /* CPU runs at MPLL/3 clock */ \
> CSCR_AHB_DIV(1) | /* AHB runs at MPLL/6 clock */ \
> + CSCR_FPM_EN | \
> CSCR_SPEN | \
> CSCR_MPEN)
>
> @@ -51,6 +52,7 @@
> CSCR_ARM_SRC_MPLL | /* use main MPLL clock */ \
> CSCR_ARM_DIV(0) | /* CPU run at full MPLL clock */ \
> CSCR_AHB_DIV(1) | /* AHB runs at MPLL/6 clock */ \
> + CSCR_FPM_EN | /* do not disable it! */ \
> CSCR_SPEN | \
> CSCR_MPEN)
>
>
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
next prev parent reply other threads:[~2011-05-25 12:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-25 16:52 Juergen Beisert
2011-05-25 12:39 ` Teresa Gamez [this message]
2011-08-25 10:02 ` Sascha Hauer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1306327199.22033.168.camel@lws-gamez \
--to=t.gamez@phytec.de \
--cc=barebox@lists.infradead.org \
--cc=jbe@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox