From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonyoung Shim Subject: Re: [PATCH 1/3 v2] Input: atmel_mxt_ts - Make wait-after-reset period compatible with all chips Date: Thu, 07 Jul 2011 09:04:49 +0900 Message-ID: <4E14F821.1000504@samsung.com> References: <4E11B8C3.8010608@atmel.com> <4E1263C9.3010704@samsung.com> <4E12B96B.2050601@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:62817 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754017Ab1GGAEe (ORCPT ); Wed, 6 Jul 2011 20:04:34 -0400 Received: from epcpsbgm1.samsung.com (mailout3.samsung.com [203.254.224.33]) by mailout3.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LNX009WWS7ECMH0@mailout3.samsung.com> for linux-input@vger.kernel.org; Thu, 07 Jul 2011 09:04:32 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LNX0098US7KX3@mmp2.samsung.com> for linux-input@vger.kernel.org; Thu, 07 Jul 2011 09:04:32 +0900 (KST) In-reply-to: <4E12B96B.2050601@atmel.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Iiro Valkonen Cc: Dmitry Torokhov , linux-input@vger.kernel.org On 2011-07-05 =EC=98=A4=ED=9B=84 4:12, Iiro Valkonen wrote: > Hello, > > On 07/05/2011 04:07 AM, Joonyoung Shim wrote: >> Hi, >> >> On 2011-07-04 =EC=98=A4=ED=9B=84 9:57, Iiro Valkonen wrote: >>> The delay before the chip can be accessed after reset varies betwee= n different >>> chips in maXTouch family. Waiting for 200ms and then monitoring the= CHG (chip >>> is ready when the line is low) is guaranteed to work with all chips= =2E >> >> I wonder 200ms waiting needs indeed, it is very long time. >> If monitoring the CHG line can detect the completion of reset, >> 200ms waiting can be removed? >> My question is monitoring the CHG line can substitute=20 "msleep(MXT_RESET_TIME)"? In other words, i want to remove msleep(MXT_RESET_TIME) and add only waiting until CHG line is low. > > Yes, 200ms is a bit longish. But it is what we need to guarantee corr= ect > functionality with all chips in all situations. I would prefer to see= that > in the mainline version. Anyone worried about the delay could maybe a= djust > the value to suit his/her needs, for example with mXT224 you could ge= t away with > using just 65ms, like in the original version. Another option would b= e to > check the family ID in the driver, and wait just long enough. Drawbac= k with > that is that the driver (possibly) needs updating with every new chip= =2E I'd > like to keep this simple& robust, wait 200ms which works for every c= urrent > (and most likely with every upcoming) chip, and take the small delay = penalty. > The 200ms delay is sometimes a problem for fastbooting, and if each chip has different delay value, i think it's better that driver support= s suitable delay value of the chip because it isn't difficult stuff. -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html