From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: Re: OMAP4 errata i740 Date: Fri, 30 Mar 2012 16:47:16 +0530 Message-ID: <4F75963C.2000508@ti.com> References: <1333094862.1932.15.camel@deskari> <1333095982.1932.21.camel@deskari> <4F756F66.6020103@ti.com> <4F757014.5030006@ti.com> <4F757262.60409@ti.com> <4F7589A3.6080104@ti.com> <4F758B15.1040905@ti.com> <4F75915D.9050205@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from arroyo.ext.ti.com ([192.94.94.40]:41146 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760189Ab2C3LRl (ORCPT ); Fri, 30 Mar 2012 07:17:41 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Shilimkar, Santosh" Cc: "Cousson, Benoit" , Tomi Valkeinen , Paul Walmsley , linux-omap , Kevin Hilman On Friday 30 March 2012 04:34 PM, Shilimkar, Santosh wrote: > On Fri, Mar 30, 2012 at 4:26 PM, Archit Taneja wrote: >> On Friday 30 March 2012 03:59 PM, Santosh Shilimkar wrote: >>> >>> On Friday 30 March 2012 03:53 PM, Cousson, Benoit wrote: >>>> >>>> On 3/30/2012 10:44 AM, Santosh Shilimkar wrote: >>>>> >>>>> On Friday 30 March 2012 02:04 PM, Archit Taneja wrote: >>>>>> >>>>>> On Friday 30 March 2012 02:01 PM, Santosh Shilimkar wrote: >>>>>>> >>>>>>> + Kevin >>>>>>> >>>>>>> On Friday 30 March 2012 01:56 PM, Tomi Valkeinen wrote: >>>>>>>> >>>>>>>> On Fri, 2012-03-30 at 13:51 +0530, Shilimkar, Santosh wrote: >>>>>>>>> >>>>>>>>> On Fri, Mar 30, 2012 at 1:37 PM, Tomi >>>>>>>>> Valkeinen wrote: >>>>>>>> >> > [...] > >> >> I had a general PRCM question regarding this. If an initiator is disabled >> (i.e, clocks are OFF and Power state is OFF), then would the PRCM even care >> to look at the IdleAck/Mstandby signal of that initiator? Or in other words, >> look at what the initiator had programmed in it's SYSCONFIG register. If it >> does consider them, it seems like that's bad HW design! >> > If a PD 9powerdomain) is already in OFF state, that means all the initiators in > that PD already has standby asserted. The modules in that > PD also have transitioned. Ah, so if DSS was configured as Nostandby, and if we try to disable DSS, it would never transition to OFF, and hence never get disabled correctly, hence giving trouble to PRCM. So just before disabling DSS, we would need to put it to Force standby, and then try to cut the clocks and change the power state. Is this correct? If so, then it's equally messy as the suggested workaround :) Archit > > So PRCM won't poke that PD initiators/modules because it has > already have a green signal for power transitions. At least that is > what my understanding from the OMAP PRCM specs. > > Regards > Santosh >