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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10FD9C49ED7 for ; Mon, 23 Sep 2019 09:14:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB8632087C for ; Mon, 23 Sep 2019 09:14:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="Z/Q8cf9e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731658AbfIWJO3 (ORCPT ); Mon, 23 Sep 2019 05:14:29 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:47198 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726363AbfIWJO2 (ORCPT ); Mon, 23 Sep 2019 05:14:28 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x8N9EMvN130460; Mon, 23 Sep 2019 04:14:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1569230062; bh=Bo3LHciudT0e3Wr5RFxKeQr9Fv9edwVOpiANXYmskNo=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=Z/Q8cf9eV1MFBKGu1OyC4oMQP6T0YS1B5ISVX+a3tX2tcvjO4Dyt9b83V89On6aKK wm/IwosRtWqOfhOq+X82+auTkVxgci7JsyhMAUzZuSfs9im2NLiYKRJqGSfQaXJyUT a8ulpXMXFtrVKRDZHBM06SmifUpS9k4o+cGqEoh0= Received: from DFLE102.ent.ti.com (dfle102.ent.ti.com [10.64.6.23]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x8N9EMnf082374 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 23 Sep 2019 04:14:22 -0500 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Mon, 23 Sep 2019 04:14:22 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Mon, 23 Sep 2019 04:14:16 -0500 Received: from [10.250.99.146] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8N9EK8P046730; Mon, 23 Sep 2019 04:14:21 -0500 Subject: Re: [PATCH v4 1/3] led: make led_set_brightness_sync() use led_set_brightness_nosleep() To: Jacek Anaszewski , , CC: , , , References: <20190920122525.15712-1-jjhiblot@ti.com> <20190920122525.15712-2-jjhiblot@ti.com> From: Jean-Jacques Hiblot Message-ID: <2172e1c7-931e-d510-648b-80ef9c606ab6@ti.com> Date: Mon, 23 Sep 2019 11:14:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacek, On 20/09/2019 23:10, Jacek Anaszewski wrote: > Hi Jean, > > On 9/20/19 2:25 PM, Jean-Jacques Hiblot wrote: >> Making led_set_brightness_sync() use led_set_brightness_nosleep() has 2 >> advantages: >> - works for LED controllers that do not provide brightness_set_blocking() >> - When the blocking callback is used, it uses the workqueue to update the >> LED state, removing the need for mutual exclusion between >> led_set_brightness_sync() and set_brightness_delayed(). > And third: > > - it compromises the "sync" part of the function name :-) Making it sync is the role of the flush_work() function. It waits until the deferred work has been done. JJ > This function has been introduced specifically to be blocking > and have the immediate effect. Its sole client is > drivers/media/v4l2-core/v4l2-flash-led-class.c. > >> Signed-off-by: Jean-Jacques Hiblot >> --- >> drivers/leds/led-core.c | 12 +++++++----- >> 1 file changed, 7 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c >> index f1f718dbe0f8..50e28a8f9357 100644 >> --- a/drivers/leds/led-core.c >> +++ b/drivers/leds/led-core.c >> @@ -294,15 +294,17 @@ EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); >> int led_set_brightness_sync(struct led_classdev *led_cdev, >> enum led_brightness value) >> { >> + int ret; >> + >> if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) >> return -EBUSY; >> >> - led_cdev->brightness = min(value, led_cdev->max_brightness); >> - >> - if (led_cdev->flags & LED_SUSPENDED) >> - return 0; >> + ret = led_set_brightness_nosleep(led_cdev, value); >> + if (!ret) >> + return ret; >> >> - return __led_set_brightness_blocking(led_cdev, led_cdev->brightness); >> + flush_work(&led_cdev->set_brightness_work); >> + return 0; >> } >> EXPORT_SYMBOL_GPL(led_set_brightness_sync); >> >>