From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 11B14156C40; Mon, 14 Jul 2025 02:38:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752460698; cv=none; b=QFSPyPt5SILFpAHzdCkF94IJob2YbNeEZ3Wgt3WUK/gTzfOaVh6gQQeH0Kuife8/9+79hAYrHxcZ7xarQWO+e9bLVOmVlK2x+ecLQjDiK3j6f98vWtLC5Op0TQ7u9nnHCqwpqh/xPPtfu1yH3AIZYMrj/xsvyhq9Np2+BV0hO5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752460698; c=relaxed/simple; bh=tBDQ6T9SB15vLOX23t6RWLMsn+1lBLsQh50/3NqT1rM=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=pojXMwpNcgxFRkfR70XD1bub19HPZFAXTSz68tV5dFt8McE7jVIqSYvE4J+PvT0V8Rndbe0riFAJkS0chMbN/4GwuEJGfLk8DkvQ6ASdzJ2hK67eRSVVvyoF3tzw/1dTof+hdoiRJBmcjTfJxtWKcgwDenDqB1qVho7OzSsJM8c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.20.42.62]) by gateway (Coremail) with SMTP id _____8CxqmqKbXRo2usoAQ--.44718S3; Mon, 14 Jul 2025 10:38:02 +0800 (CST) Received: from [10.20.42.62] (unknown [10.20.42.62]) by front1 (Coremail) with SMTP id qMiowJAxE+SDbXRoXzwWAA--.55950S3; Mon, 14 Jul 2025 10:37:57 +0800 (CST) Subject: Re: [PATCH] rtc: efi: Add runtime check for the wakeup service capability To: Ard Biesheuvel , Alexandre Belloni Cc: Feng Tang , linux-rtc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250710084151.55003-1-feng.tang@linux.alibaba.com> <20250711085608f4146d99@mail.local> From: Bibo Mao Message-ID: Date: Mon, 14 Jul 2025 10:36:19 +0800 User-Agent: Mozilla/5.0 (X11; Linux loongarch64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Precedence: bulk X-Mailing-List: linux-rtc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-CM-TRANSID:qMiowJAxE+SDbXRoXzwWAA--.55950S3 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBj93XoWxurWrJFyxJryxAry8ArWDAwc_yoW5XrWfpF WUCFWqqr15KFy8Ars2qw1Y9r1aqry3tFy8Xw1DAa4UWrn0vr1jkr40kr4Y9a9FgryrC3WY 9Fy2qF9I93WDAagCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBFb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU XVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcVAKI4 8JMxk0xIA0c2IEe2xFo4CEbIxvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_ Jr0_Gr1l4IxYO2xFxVAFwI0_Jrv_JF1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8Gjc xK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0 cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8V AvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E 14v26r1j6r4UYxBIdaVFxhVjvjDU0xZFpf9x07jepB-UUUUU= On 2025/7/14 上午10:08, Ard Biesheuvel wrote: > On Fri, 11 Jul 2025 at 18:56, Alexandre Belloni > wrote: >> >> On 11/07/2025 11:26:18+1000, Ard Biesheuvel wrote: >>> On Fri, 11 Jul 2025 at 11:06, Ard Biesheuvel wrote: >>>> >>>> On Thu, 10 Jul 2025 at 18:41, Feng Tang wrote: >>>>> >>>>> The kernel selftest of rtc reported a error on an ARM server which >>>>> use rtc-efi device: >>>>> >>>>> RUN rtc.alarm_alm_set ... >>>>> rtctest.c:262:alarm_alm_set:Alarm time now set to 17:31:36. >>>>> rtctest.c:267:alarm_alm_set:Expected -1 (-1) != rc (-1) >>>>> alarm_alm_set: Test terminated by assertion >>>>> FAIL rtc.alarm_alm_set >>>>> not ok 5 rtc.alarm_alm_set >>>>> >>>>> The root cause is, the underlying EFI firmware doesn't support wakeup >>>>> service (get/set alarm), while it doesn't have the EFI RT_PROP table >>>>> either. As Ard Biesheuvel clarified [1], this breaks the UEFI spec, >>>>> which requires EFI firmware to provide a 'RT_PROP' table if it doesn't >>>>> support all runtime services (Section 4.6.2, UEFI spec 2.10). >>>>> >>>>> This issue was also reproduced on ARM server from another vendor, which >>>>> doesn't have RT_PROP table either. This means, in real world, there are >>>>> quite some platforms having this issue, that it doesn't support wakeup >>>>> service while not providing a correct RT_PROP table, which makes it >>>>> wrongly claimed to support it. >>>>> >>>>> Add a runtime check for the wakeup service to detect and correct this >>>>> kind of cases. >>>>> >>>>> [1]. https://lore.kernel.org/lkml/CAMj1kXEkzXsjm0dPhzxB+KdtzqADd4NmafKmw2rKw7mAPBrgdA@mail.gmail.com/ >>>>> >>>>> Signed-off-by: Feng Tang >>>>> --- >>>>> drivers/rtc/rtc-efi.c | 4 +++- >>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>> >>>> >>>> Thanks, I've queued this up now. >>>> >>> >>> Actually, we might just remove the EFI get/set wakeup time >>> functionality altogether, as it seems rather pointless to me to begin >>> with. >>> >>> I'll send out an RFC shortly. >> >> I guess this is going to also solve the issue reported by loongson >> https://lore.kernel.org/linux-rtc/20250613061747.4117470-1-wangming01@loongson.cn/ >> >> However, please let me take care of patches in my subsystem... >> > > Apologies - I've dropped it now. > > But please don't queue this, I'll send out my RFC shortly. > This is similar problem on Loongarch VM when running ltp testcase rtc02, I do not know whether the root cause is the same, the runtime service is hard to debug. Hope for RFC version :) Regards Bibo Mao