Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752867AbaFPCoh (ORCPT ); Sun, 15 Jun 2014 22:44:37 -0400 Received: from mga11.intel.com ([192.55.52.93]:8227 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbaFPCof (ORCPT ); Sun, 15 Jun 2014 22:44:35 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,483,1400050800"; d="scan'208";a="555988744" Message-ID: <539E59D3.7080508@intel.com> Date: Mon, 16 Jun 2014 10:43:31 +0800 From: Lan Tianyu User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: "Zheng, Lv" CC: David Rientjes , "rjw@rjwysocki.net" , "lenb@kernel.org" , "naszar@ya.ru" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ACPI/Battery: Retry to get Battery information if failed during probing References: <1402552946-14704-1-git-send-email-tianyu.lan@intel.com> <53995488.20308@intel.com> <53996152.2000407@intel.com> <539A60FC.1050301@intel.com> <539E528B.90908@intel.com> <1AE640813FDE7649BE1B193DEA596E880262DA59@SHSMSX101.ccr.corp.intel.com> In-Reply-To: <1AE640813FDE7649BE1B193DEA596E880262DA59@SHSMSX101.ccr.corp.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014年06月16日 10:35, Zheng, Lv wrote: > Hi, > >> From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-owner@vger.kernel.org] On Behalf Of Lan Tianyu >> Sent: Monday, June 16, 2014 10:12 AM >> To: David Rientjes >> Cc: rjw@rjwysocki.net; lenb@kernel.org; naszar@ya.ru; linux-acpi@vger.kernel.org; linux-kernel@vger.kernel.org >> Subject: Re: [PATCH] ACPI/Battery: Retry to get Battery information if failed during probing >> >> On 2014年06月14日 05:46, David Rientjes wrote: >>> On Fri, 13 Jun 2014, Lan Tianyu wrote: >>> >>>> How about this? >>>> >>>> - result = acpi_battery_update(battery, false); >>>> - if (result) >>>> + >>>> + /* >>>> + * Some machines'(E,G Lenovo Z480) ECs are not stable > > Just a reminder. > > This statement may not be true. > The issue may be caused by the EC driver itself. > So we need to investigate. Not sure. The bug doesn't happen every time. 5-10% during boot up. > >>>> + * during boot up and this causes battery driver fails to be >>>> + * probed due to failure of getting battery information >>>> + * from EC sometimes. After several retries, the operation >>>> + * may work. So add retry code here and 20ms sleep between >>>> + * every retries. >>>> + */ >>>> + while (acpi_battery_update(battery, false) && retry--) > > If EC hardware is stable, why we need to do retry here? > Yes, if it can work normally every time, we don't need retry here. > Thanks and best regards > -Lv > >>>> + msleep(20); >>>> + if (!retry) { >>>> + result = -ENODEV; >>>> goto fail; >>>> + } >>>> + >>> >>> I think you want --retry and not retry--. >> >> My original purpose is to retry 5 times after the first try fails. >> If use "--retry" here, it just retries 4 times. >> >>> Otherwise it's possible for the >>> final call to acpi_battery_update() to succeed and now it's returning >>> -ENODEV. >>> >> >> Yes, it maybe and I will change code like the following. >> >> while ((result = acpi_battery_update(battery, false)) && retry--) >> msleep(20); >> if (result) >> goto fail; >> >> >> -- >> Best regards >> Tianyu Lan >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/