From patchwork Mon Oct 16 10:06:37 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeffy Chen X-Patchwork-Id: 10008013 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 86040601D5 for ; Mon, 16 Oct 2017 10:08:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6DADB28437 for ; Mon, 16 Oct 2017 10:08:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6214A28449; Mon, 16 Oct 2017 10:08:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 141B228437 for ; Mon, 16 Oct 2017 10:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751743AbdJPKHZ (ORCPT ); Mon, 16 Oct 2017 06:07:25 -0400 Received: from regular1.263xmail.com ([211.150.99.134]:43461 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750914AbdJPKHY (ORCPT ); Mon, 16 Oct 2017 06:07:24 -0400 Received: from jeffy.chen?rock-chips.com (unknown [192.168.167.225]) by regular1.263xmail.com (Postfix) with ESMTP id 69D149158; Mon, 16 Oct 2017 18:07:20 +0800 (CST) X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 Received: from localhost (localhost [127.0.0.1]) by smtp.263.net (Postfix) with ESMTPA id 4BD813AF; Mon, 16 Oct 2017 18:07:15 +0800 (CST) X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: <5817a95200219ba3759556c48c858066> X-ATTACHMENT-NUM: 0 X-SENDER: cjf@rock-chips.com X-DNS-TYPE: 0 Received: from localhost (unknown [103.29.142.67]) by smtp.263.net (Postfix) whith ESMTP id 1645Y2R7NP; Mon, 16 Oct 2017 18:07:21 +0800 (CST) From: Jeffy Chen To: linux-kernel@vger.kernel.org Cc: dmitry.torokhov@gmail.com, heiko@sntech.de, briannorris@chromium.org, rjw@rjwysocki.net, dianders@chromium.org, tfiga@chromium.org, broonie@kernel.org, seanpaul@chromium.org, Jeffy Chen , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, Daniel Thompson , Thierry Reding , Bartlomiej Zolnierkiewicz , dri-devel@lists.freedesktop.org, Jingoo Han , Lee Jones Subject: [RESEND PATCH v2 2/5] backlight: pwm_bl: Add device link for pwm_bl and pwm Date: Mon, 16 Oct 2017 18:06:37 +0800 Message-Id: <20171016100640.26575-3-jeffy.chen@rock-chips.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171016100640.26575-1-jeffy.chen@rock-chips.com> References: <20171016100640.26575-1-jeffy.chen@rock-chips.com> Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When the pwm driver is unbound, the pwm_bl driver would still hold a reference to that pwm, and crash the kernel later(if someone trying to access that invalid pwm). Add a device link to avoid this. Signed-off-by: Jeffy Chen --- Changes in v2: None drivers/video/backlight/pwm_bl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 9bd17682655a..a76f147a26e7 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -328,6 +328,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } + device_link_add(&pdev->dev, pb->pwm->chip->dev, DL_FLAG_AUTOREMOVE); + dev_dbg(&pdev->dev, "got pwm for backlight\n"); /*