From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F15BBC433FE for ; Wed, 27 Oct 2021 02:18:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8695610A1 for ; Wed, 27 Oct 2021 02:18:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237752AbhJ0CVE (ORCPT ); Tue, 26 Oct 2021 22:21:04 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:56612 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232231AbhJ0CVD (ORCPT ); Tue, 26 Oct 2021 22:21:03 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R761e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0Utq7SVb_1635301115; Received: from B-J4ZXMD6R-0327.local(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0Utq7SVb_1635301115) by smtp.aliyun-inc.com(127.0.0.1); Wed, 27 Oct 2021 10:18:37 +0800 Subject: Re: [PATCH v3] ACPI, APEI, EINJ: Relax platform response timeout to 1 second. To: "Luck, Tony" , "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, bp@alien8.de, james.morse@arm.com, lenb@kernel.org, rjw@rjwysocki.net, zhangliguang@linux.alibaba.com, zhuo.song@linux.alibaba.com References: <20211015033817.16719-1-xueshuai@linux.alibaba.com> <20211026072829.94262-1-xueshuai@linux.alibaba.com> From: Shuai Xue Message-ID: Date: Wed, 27 Oct 2021 10:18:35 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tony, Thank you for your patient revision. :) Cheers, Shuai On 2021/10/27 AM1:05, Luck, Tony wrote: > On Tue, Oct 26, 2021 at 03:28:29PM +0800, Shuai Xue wrote: >> When injecting an error into the platform, the OSPM executes an >> EXECUTE_OPERATION action to instruct the platform to begin the injection >> operation. And then, the OSPM busy waits for a while by continually >> executing CHECK_BUSY_STATUS action until the platform indicates that the >> operation is complete. More specifically, the platform is limited to >> respond within 1 millisecond right now. This is too strict for some >> platforms. >> >> For example, in Arm platform, when injecting a Processor Correctable error, >> the OSPM will warn: >> Firmware does not respond in time. >> >> And a message is printed on the console: >> echo: write error: Input/output error >> >> We observe that the waiting time for DDR error injection is about 10 ms and >> that for PCIe error injection is about 500 ms in Arm platform. >> >> In this patch, we relax the response timeout to 1 second. >> >> Signed-off-by: Shuai Xue > > Reviewed-by: Tony Luck > > Rafael: Do you want to take this in the acpi tree? If not, I can > apply it to the RAS tree (already at -rc7, so in next merge cycle > after 5.16-rc1 comes out). > >> --- >> Changelog v2 -> v3: >> - Implemented the timeout in usleep_range instead of msleep. >> - Dropped command line interface of timeout. >> - Link to the v1 patch: https://lkml.org/lkml/2021/10/14/1402 >> --- >> drivers/acpi/apei/einj.c | 15 ++++++++------- >> 1 file changed, 8 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c >> index 133156759551..6e1ff4b62a8f 100644 >> --- a/drivers/acpi/apei/einj.c >> +++ b/drivers/acpi/apei/einj.c >> @@ -28,9 +28,10 @@ >> #undef pr_fmt >> #define pr_fmt(fmt) "EINJ: " fmt >> >> -#define SPIN_UNIT 100 /* 100ns */ >> -/* Firmware should respond within 1 milliseconds */ >> -#define FIRMWARE_TIMEOUT (1 * NSEC_PER_MSEC) >> +#define SLEEP_UNIT_MIN 1000 /* 1ms */ >> +#define SLEEP_UNIT_MAX 5000 /* 5ms */ >> +/* Firmware should respond within 1 seconds */ >> +#define FIRMWARE_TIMEOUT (1 * USEC_PER_SEC) >> #define ACPI5_VENDOR_BIT BIT(31) >> #define MEM_ERROR_MASK (ACPI_EINJ_MEMORY_CORRECTABLE | \ >> ACPI_EINJ_MEMORY_UNCORRECTABLE | \ >> @@ -171,13 +172,13 @@ static int einj_get_available_error_type(u32 *type) >> >> static int einj_timedout(u64 *t) >> { >> - if ((s64)*t < SPIN_UNIT) { >> + if ((s64)*t < SLEEP_UNIT_MIN) { >> pr_warn(FW_WARN "Firmware does not respond in time\n"); >> return 1; >> } >> - *t -= SPIN_UNIT; >> - ndelay(SPIN_UNIT); >> - touch_nmi_watchdog(); >> + *t -= SLEEP_UNIT_MIN; >> + usleep_range(SLEEP_UNIT_MIN, SLEEP_UNIT_MAX); >> + >> return 0; >> } >> >> -- >> 2.20.1.12.g72788fdb >>