From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Shilimkar, Santosh" Subject: Re: L2 cache stability workaround for 4460 ES1.0 Date: Mon, 2 Apr 2012 14:43:29 +0530 Message-ID: References: <4F794D5D.3090509@ti.com> <4F795B76.3030002@ti.com> <4F795D02.8010705@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from na3sys009aog110.obsmtp.com ([74.125.149.203]:55058 "EHLO na3sys009aog110.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751563Ab2DBJNv (ORCPT ); Mon, 2 Apr 2012 05:13:51 -0400 Received: by qcsu28 with SMTP id u28so1851585qcs.22 for ; Mon, 02 Apr 2012 02:13:50 -0700 (PDT) In-Reply-To: <4F795D02.8010705@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Roger Quadros Cc: "Dechesne, Nicolas" , "linux-omap@vger.kernel.org" On Mon, Apr 2, 2012 at 1:32 PM, Roger Quadros wrote: > On 04/02/2012 10:58 AM, Shilimkar, Santosh wrote: >> On Mon, Apr 2, 2012 at 1:25 PM, Roger Quadros wrote: >>> On 04/02/2012 10:38 AM, Shilimkar, Santosh wrote: >>>> On Mon, Apr 2, 2012 at 12:25 PM, Roger Quadros wrote: >>>>> Hi Santosh, >>>>> >>>>> I came across the attached patch from you. I also came across this post >>>>> stating that it was decided not to send this patch upstream. >>>>> >>>>> http://www.digipedia.pl/usenet/thread/18885/8437/#post8496 >>>>> >>>>> The problem is that we have to keep porting this patch each time we >>>>> update the kernel. >>>>> >>>>> Do you know if the root cause has been found? If not can we have this >>>>> patch upstream till the root cause is found? >>>>> >>>> Yes and fixed in OMAP4460 ES1.2. >>> >>> Did you mean ES1.1? >>> >> yep. Sorry for the typo. >> >>> Could you please point me to the errata ID? The only cache related >>> errata I can see is Errata ID: i690 >>> >>>> >>>>> It seems the patch at least makes the kernel usable on ES1.0. >>>>> >>>> I know but that still is not enough. It's like 80 % WA of the issue >>>> seen on ES1.0. We are not suppose to have many boards with >>>> ES1.0 >>>> >>> Even better if there are not many boards. It seems most of the boards >>> will be with TI. I think we should have the fix in even if it is not >>> 100% fix. >>> >>> What do you say? >>> >> My request is to get rid of ES1.0 board because the WA just >> not completely correct. Don't feel patching kernel for silicon >> which is not suppose to be used nether has complete WA >> to support it. >> > OK Santosh. seems like cache is broken bad on ES1.0. > > Is it possible to disable the cache for ES1.0 and print a warning > message about it? > Let's not add that support. See there are very few boards in TI where ES1.0 is used so I suggest those users keep using whatever works for them. Disable or the partial WA. Regards Santosh