From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932985Ab3CUNzm (ORCPT ); Thu, 21 Mar 2013 09:55:42 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:60012 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757334Ab3CUNzk (ORCPT ); Thu, 21 Mar 2013 09:55:40 -0400 Message-ID: <514B1154.1020100@ti.com> Date: Thu, 21 Mar 2013 15:55:32 +0200 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Roger Quadros CC: , , , , , , Subject: Re: [PATCH] ARM: OMAP4: clock: Initialize USB DPLL References: <1363873705-3224-1-git-send-email-rogerq@ti.com> In-Reply-To: <1363873705-3224-1-git-send-email-rogerq@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/21/2013 03:48 PM, Roger Quadros wrote: > If the bootloader doesn't configure USB DPLL (e.g. in u-boot, > disable CONFIG_USB_EHCI_OMAP), then we get all sorts of problems > like > - division by zero errors at boot [1] > - USB DPLL fails to enter locked state > - USB EHCI Host is non functional > - Device can't enter OFF mode > > Initializing the USB DPLL fixes all these issues. > > [1] > > [ 0.000000] clock: dpll_usb_ck failed transition to 'locked' > [ 0.000000] Division by zero in kernel. > [ 0.000000] [] (unwind_backtrace+0x0/0xf0) from [] (Ldiv0+0x8/0x10) > [ 0.000000] [] (Ldiv0+0x8/0x10) from [] (clk_divider_set_rate+0x10/0x124) > [ 0.000000] [] (clk_divider_set_rate+0x10/0x124) from [] (clk_change_rate+0x3c/0xb4) > [ 0.000000] [] (clk_change_rate+0x3c/0xb4) from [] (clk_change_rate+0xa0/0xb4) > > Signed-off-by: Roger Quadros > --- > arch/arm/mach-omap2/cclock44xx_data.c | 19 +++++++++++++++++++ > 1 files changed, 19 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-omap2/cclock44xx_data.c b/arch/arm/mach-omap2/cclock44xx_data.c > index bfc46c1..6127bb9 100644 > --- a/arch/arm/mach-omap2/cclock44xx_data.c > +++ b/arch/arm/mach-omap2/cclock44xx_data.c > @@ -53,6 +53,12 @@ > */ > #define OMAP4_DPLL_ABE_DEFFREQ 98304000 > > +/* > + * OMAP4450 TRM Rev X, section "3.6.3.9.5 DPLL_USB Preferred Settings" 4460 actually. cheers, -roger