From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Cousson, Benoit" Subject: Re: OMAP4 errata i740 Date: Fri, 30 Mar 2012 14:00:42 +0200 Message-ID: <4F75A06A.80201@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> <4F75963C.2000508@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:38228 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934311Ab2C3MAr (ORCPT ); Fri, 30 Mar 2012 08:00:47 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Shilimkar, Santosh" Cc: Archit Taneja , Tomi Valkeinen , Paul Walmsley , linux-omap , Kevin Hilman On 3/30/2012 1:20 PM, Shilimkar, Santosh wrote: > On Fri, Mar 30, 2012 at 4:47 PM, Archit Taneja wrote: >> 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 :) >> > Exactly. That's what I mean. You tweak sysconfig or clockdomain, > both are messy. Not it's not. We are trying to avoid accessing the sysconfig from the driver, but at least this is a setting local to the IP. And as you said, we have to do that already do to the various bugs here and there on a lot of IPs. Playing with clock domain state from the driver is just not acceptable. > if one need to choose between two bad options, I guess sysconifig > one is better because that is local to IPs and there is some way today > for drivers to manage sysconfig directly. Yes, that's the point. Benoit