From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QwWlZ-0007fo-Iz for barebox@lists.infradead.org; Thu, 25 Aug 2011 10:02:30 +0000 Date: Thu, 25 Aug 2011 12:02:27 +0200 From: Sascha Hauer Message-ID: <20110825100227.GA4128@pengutronix.de> References: <201011251752.42159.jbe@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <201011251752.42159.jbe@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] phyCORE-i.MX27: Keep frequency multiplier enabled to be able to do a warmstart To: Juergen Beisert Cc: barebox@lists.infradead.org On Thu, Nov 25, 2010 at 05:52:42PM +0100, Juergen Beisert wrote: > commit 7d25a0552dd3a4b65412ae1cbf8f9ca8a88b5d27 > Author: Juergen Beisert > 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 Applied to master. Maintainer was asleep for a long long time. Sascha > > 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) > > > -- > Pengutronix e.K. | Juergen Beisert | > Linux Solutions for Science and Industry | Phone: +49-8766-939 228 | > Vertretung Sued/Muenchen, Germany | Fax: +49-5121-206917-5555 | > Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de/ | > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox