From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f180.google.com (mail-pf1-f180.google.com [209.85.210.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4035354727; Thu, 19 Dec 2024 03:50:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734580217; cv=none; b=WBa2DXiu13CnFGM4mUhsgKrb474I+56z+rf4xk06z8PHUrlYm/Ub3d5Eva1lKcuXTAgmhOIMklW6DcbP2Q8O7f6jbeTs1Z/k0pHorVBu0WR37bLVoU7j1XCsGb4hzbgxHBmogh+vsZTIrR5zPx7xHNZEowEGK9Z4nRSGBYFH5qo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734580217; c=relaxed/simple; bh=/c5kyZvSoZodl4OuOHRv3XBuU1rpIGinCqzAmQ63/QM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UpAvq+/RorW9dEsHLrSJOq+dTQQKVwEphP/fETwwuBshYWiLiwNx8UR1BkiSoFBcfR12r52Wl/zy204TwuFFzyDG10XqRHNy2TV2qZiMQtjSrpDLWQdROn8phMK3HHLCQSKrx6Q8E5gx2fUOjJCUZGBgdxJsJU/Sx7arj5GDqLg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fyLiv4LV; arc=none smtp.client-ip=209.85.210.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fyLiv4LV" Received: by mail-pf1-f180.google.com with SMTP id d2e1a72fcca58-725abf74334so309890b3a.3; Wed, 18 Dec 2024 19:50:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1734580214; x=1735185014; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:from:to:cc:subject:date:message-id:reply-to; bh=P/RXSdlYCurZNt7gHEJldKTq68jBWsZpzA3EWLVNuY4=; b=fyLiv4LVrboHffuKOMQOQyoXVsGgSNo6dgUkcr1wRh/CnGavwVpTIMVJXC+qSB6T81 nUr+KhQkmj5XERyU/kBMjG6MORanKFwKt/A9maCGEgXwCA57Nmqu4vIUMR19JyrmwiRI /Zp+SgjU1bPOtNFJmWT4dYEYvZVA/IUok7nftKrh9sc56YfEdc8WCeQ7hV58I58RO8vN +c1rRy6f4A6FdbhM5YorJpJdCU7ZsPZnCQ3kkOsT7hYYhIi8LlT3yBsty+rqG5hc2iW5 ooEJIUkJpG9gUDx+UBWgk5+zSsYO4jM0h6z445JdjYTMrKaALcRkWMy9fpv7fbzxRPU1 iWYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1734580214; x=1735185014; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=P/RXSdlYCurZNt7gHEJldKTq68jBWsZpzA3EWLVNuY4=; b=PIPI8Xn/szifx0lEtwFZEUSVEV+kAf3cvGKkW0pCUdxvyefIzKhcNUfRMc6JHHNvaq XBhTjUV23o9Zk1ZUgy9WaYo/YkaJyvbZJRSslL515DdH/JSiTFFIh/zY9z+jLzut5HO2 R4zaVEBv1Cwpj3kQrHlY0luP/BcR6h0WwsvgKyW8IcPbTrRnyRurpu4W8Ge5zZWiFPaV 2GDMJgOXTKKUqTGJ/0TNarJUQwOeAgq18t4VpCYCfJ2J7MzOIieMZxoqdoGH/5SsIgxi If2rW+i6MRrWDxu+c5UUNSrAPF0TpoFIdetVxONA7Q5G4tY2SaKLCsjOjH3IMzni/LAl t7ZQ== X-Forwarded-Encrypted: i=1; AJvYcCWplERFgYyxE334lCu9dAeDWsFxMx/PT6Pms6SlvxfIZmlkkBZNOrLVlyC3sXkLM56iOez2jQJWyzgDq8lk@vger.kernel.org, AJvYcCXVExS8TcaZA597PUWyzEwQjJf/NYUTKE4yfAgLcxkgQENr7h6WkI4l4vnVVWFIvy5Wjx6DxlT+D/CVRg==@vger.kernel.org X-Gm-Message-State: AOJu0YwcWo24QsIOfX0XqvYclOcFXktc74KanMFjBH7ypYGkrXVO3QSq dY3d4GM8ZkwuCVCfvgfdBkr4b+uvnsaKbHg/GHw/iG5By8JIse87 X-Gm-Gg: ASbGncuMVg7G6bbE6NZwGEq8r+OLh8azkczL/R8S8QaLBbNqifYOUwGV8qDLeE9Igkq q7uxeTstG8ke2nFj53qaI3ii4MO/+jKyEk+kugd9Eaz3ysVQGP3z4giDH/WyeBTUBNNy6xue+FS NOBQbEjI8kOvPVesfBng8hC8+LOsMeajL8/9KT+cEem+1vSWze0N/P3Dy4f/DnIQjW4SJPc1Z4C XOSeB0SrjaVdBetK0IWgDdflsj2n1Qe4yASbRdUZaLu1aM2CA9MGTgB7Bs4TQvAtpu9rIlvrqxc cTb5mNVvAc+/1rhyExP6NDTY7AVo4Q== X-Google-Smtp-Source: AGHT+IEgR/olPlTuq1cflAd0ilh1YPOb4/Y4cRuTVkc+Dlbaj10rqBVjRqco6nU+77LTtvzd6iJ4Kw== X-Received: by 2002:a05:6a20:728b:b0:1e1:aab8:3887 with SMTP id adf61e73a8af0-1e5b489b0abmr10161474637.39.1734580214278; Wed, 18 Dec 2024 19:50:14 -0800 (PST) Received: from ?IPV6:2600:1700:e321:62f0:da43:aeff:fecc:bfd5? ([2600:1700:e321:62f0:da43:aeff:fecc:bfd5]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-842e32f7ea0sm205840a12.78.2024.12.18.19.50.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Dec 2024 19:50:13 -0800 (PST) Sender: Guenter Roeck Message-ID: Date: Wed, 18 Dec 2024 19:50:11 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/4] hwmon: (acpi_power_meter) Fix using uninitialized variables To: "lihuisong (C)" , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jdelvare@suse.com, liuyonglong@huawei.com, zhanjie9@hisilicon.com, zhenglifeng1@huawei.com References: <20241125093415.21719-1-lihuisong@huawei.com> <20241125093415.21719-2-lihuisong@huawei.com> <77fce1aa-96eb-4c3c-ab0a-a33de46b333b@roeck-us.net> <87367d88-b10e-29d6-2712-f8f5c24e52a4@huawei.com> <1ce7718c-0bf8-4009-9240-fc6e2363ed54@roeck-us.net> <2068a450-7752-c47b-edfc-cb2a00ac4402@huawei.com> Content-Language: en-US From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+ J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 12/18/24 19:45, lihuisong (C) wrote: > > 在 2024/12/12 11:00, lihuisong (C) 写道: >> >> 在 2024/12/12 9:51, Guenter Roeck 写道: >>> On 11/26/24 19:43, lihuisong (C) wrote: >>>> Hi Guenter， >>>> >>>> How about the modification as below? But driver doesn't know what the time is to set resource->power_alarm to false. >>>> >>> It's a start, but incomplete because power_alarm must be reset. >>> >>> See below. >>> >>>> 在 2024/11/27 0:19, Guenter Roeck 写道: >>>>> On 11/25/24 23:03, lihuisong (C) wrote: >>>>>> >>>>>> 在 2024/11/26 12:04, Guenter Roeck 写道: >>>>>>> On 11/25/24 17:56, lihuisong (C) wrote: >>>>>>>> Hi Guente, >>>>>>>> >>>>>>>> Thanks for your timely review. >>>>>>>> >>>>>>>> 在 2024/11/26 0:03, Guenter Roeck 写道: >>>>>>>>> On 11/25/24 01:34, Huisong Li wrote: >>>>>>>>>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>>>>>>>>> acpi_power_meter_resource structure. However, these two fields are just >>>>>>>>>> updated when user query 'power' and 'cap' attribute, or hardware enforced >>>>>>>>>> limit. If user directly query the 'power1_alarm' attribute without queryng >>>>>>>>>> above two attributes, driver will use the uninitialized variables to judge. >>>>>>>>>> In addition, the 'power1_alarm' attribute needs to update power and cap to >>>>>>>>>> show the real state. >>>>>>>>>> >>>>>>>>>> Signed-off-by: Huisong Li >>>>>>>>>> --- >>>>>>>>>>   drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>>>>>>>>>   1 file changed, 10 insertions(+) >>>>>>>>>> >>>>>>>>>> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c >>>>>>>>>> index 2f1c9d97ad21..4c3314e35d30 100644 >>>>>>>>>> --- a/drivers/hwmon/acpi_power_meter.c >>>>>>>>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>>>>>>>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>>>>>>>>>       struct acpi_device *acpi_dev = to_acpi_device(dev); >>>>>>>>>>       struct acpi_power_meter_resource *resource = acpi_dev->driver_data; >>>>>>>>>>       u64 val = 0; >>>>>>>>>> +    int ret; >>>>>>>>>> + >>>>>>>>>> +    guard(mutex)(&resource->lock); >>>>>>>>>>         switch (attr->index) { >>>>>>>>>>       case 0: >>>>>>>>>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>>>>>>>>>               val = 0; >>>>>>>>>>           break; >>>>>>>>>>       case 6: >>>>>>>>>> +        ret = update_meter(resource); >>>>>>>>>> +        if (ret) >>>>>>>>>> +            return ret; >>>>>>>>>> +        ret = update_cap(resource); >>>>>>>>>> +        if (ret) >>>>>>>>>> +            return ret; >>>>>>>>>> + >>>>>>>>>>           if (resource->power > resource->cap) >>>>>>>>>>               val = 1; >>>>>>>>>>           else >>>>>>>>> >>>>>>>>> >>>>>>>>> While technically correct, the implementation of this attribute defeats its >>>>>>>>> purpose. It is supposed to reflect the current status as reported by the >>>>>>>>> hardware. A real fix would be to use the associated notification to set or >>>>>>>>> reset a status flag, and to report the current value of that flag as reported >>>>>>>>> by the hardware. >>>>>>>> I know what you mean. >>>>>>>> The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. >>>>>>>> It's good, but it depands on hardware support notification. >>>>>>>>> >>>>>>>>> If there is no notification support, the attribute should not even exist, >>>>>>>>> unless there is a means to retrieve its value from ACPI (the status itself, >>>>>>>>> not by comparing temperature values). >>>>>>>> Currently, the 'power1_alarm' attribute is created just when platform support the power meter meassurement(bit0 of the supported capabilities in _PMC). >>>>>>>> And it doesn't see if the platform support notifications. >>>>>>>>  From the current implementation of this driver, this sysfs can also reflect the status by comparing power and cap, >>>>>>>> which is good to the platform that support hardware limit from some out-of-band mechanism but doesn't support any notification. >>>>>>>> >>>>>>> >>>>>>> The point is that this can also be done from userspace. Hardware monitoring drivers >>>>>>> are supposed to provide hardware attributes, not software attributes derived from it. >>>>>>> >>>>>> So this 'power1_alarm' attribute can be exposed when platform supports hardware enforced limit and notifcations when the hardware limit is enforced, right? >>>>>> If so, we have to change the condition that driver creates this sysfs interface. >>>>> >>>>> This isn't about enforcing anything, it is about reporting an alarm >>>>> if the power consumed exceeds the maximum configured. >>>>> >>>> --> >>>> >>>> index 2f1c9d97ad21..b436ebd863e6 >>>> --- a/drivers/hwmon/acpi_power_meter.c >>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>> @@ -84,6 +84,7 @@ struct acpi_power_meter_resource { >>>>          u64             power; >>>>          u64             cap; >>>>          u64             avg_interval; >>>> +       bool            power_alarm; >>>>          int                     sensors_valid; >>>>          unsigned long           sensors_last_updated; >>>>          struct sensor_device_attribute  sensors[NUM_SENSORS]; >>>> @@ -396,6 +397,9 @@ static ssize_t show_val(struct device *dev, >>>>          struct acpi_device *acpi_dev = to_acpi_device(dev); >>>>          struct acpi_power_meter_resource *resource = acpi_dev->driver_data; >>>>          u64 val = 0; >>>> +       int ret; >>>> + >>>> +       guard(mutex)(&resource->lock); >>>> >>>>          switch (attr->index) { >>>>          case 0: >>>> @@ -423,10 +427,21 @@ static ssize_t show_val(struct device *dev, >>>>                          val = 0; >>>>                  break; >>>>          case 6: >>>> -               if (resource->power > resource->cap) >>>> -                       val = 1; >>>> -               else >>>> -                       val = 0; >>>> +               /* report alarm status based on the notification if support. */ >>>> +               if (resource->caps.flags & POWER_METER_CAN_NOTIFY) { >>>> +                       val = resource->power_alarm; >>>> +               } else { >>>> +                       ret = update_meter(resource); >>>> +                       if (ret) >>>> +                               return ret; >>>> +                       ret = update_cap(resource); >>>> +                       if (ret) >>>> +                               return ret; >>>> +                       if (resource->power > resource->cap) >>>> +                               val = 1; >>>> +                       else >>>> +                               val = 0; >>>> +               } >>> >>> It would have to be something like >>> >>>         ret = update_meter(resource); >>>         if (ret) >>>             return ret; >>> >>>         val = resource->power_alarm || resource->power > resource->cap; >>>         /* clear alarm if no longer active */ >>>         resource->power_alarm &= resource->power > resource->cap; >>> >>> This ensures that alarms are cached if supported, and that cached values are >>> reported at once. It is far from perfect but the best I can think of since >>> there is no notification that the alarm is cleared. >>> >> Indeed, since there is no notification that the alarm is cleared, driver have to compare 'power' and 'cap' to clear it anyway. >> If platform support notify to OSPM, driver also need to update 'power' to show this alarm status. >> In this case, no need to update 'cap' which can be updated by nofity 0x82 event, right? But this also depands on the initialization of the "resource->cap" the probe phase needs to add. >> For the platform doesn't support notify, driver have to update 'cap' and 'power' to show this status, right? >> >> But considering above two cases, directly to update 'power' and 'cap' is simple to handle this without more switch case. >> what do you think, Guenter? > > Hi Guenter, > > What do you think? Looking forward to your reply.😁 > This is getting too complicated for a reply after a casual glance at the driver, and I don't currently have time for a deeper look into the driver, sorry. Guenter > /Huisong Li > >>> >>>>                  break; >>>>          case 7: >>>>          case 8: >>>> @@ -853,6 +868,7 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event) >>>>                  sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME); >>>>                  break; >>>>          case METER_NOTIFY_CAPPING: >>>> +               resource->power_alarm = true; >>>>                  sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME); >>>>                  dev_info(&device->dev, "Capping in progress.\n"); >>>>                  break; >>>> >>>>> . >>>> >>> >>> >>> . >> >> .