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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 AB0E8C07E94 for ; Fri, 4 Jun 2021 16:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A93961405 for ; Fri, 4 Jun 2021 16:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230192AbhFDQMh (ORCPT ); Fri, 4 Jun 2021 12:12:37 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:49232 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230153AbhFDQMg (ORCPT ); Fri, 4 Jun 2021 12:12:36 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1622823050; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=7OrD0eroTm8+Xh/p6MsHyA4aVI8DyLGbpiIhRk9+tQI=; b=mRjZlFs3xIHN3FbjHB2TCzS6RbD+XS2mbnbHg97mvVqC1tVT+zdCmoSV4Z4YklMpa50ZLcY/ qL9Olx7FmFQoX8WMP/mrFNNnk5nU/UxgeaMfiwl+YWxVXT0nWD0XW5cVlmzbKqLy2//0Mim1 +kQfF386eaW5HcjDgjYNV9XO5uM= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-east-1.postgun.com with SMTP id 60ba5076abfd22a3dc9e411b (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 04 Jun 2021 16:10:30 GMT Sender: rajeevny=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 9B79DC43147; Fri, 4 Jun 2021 16:10:29 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: rajeevny) by smtp.codeaurora.org (Postfix) with ESMTPSA id AC24EC433F1; Fri, 4 Jun 2021 16:10:28 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 04 Jun 2021 21:40:28 +0530 From: rajeevny@codeaurora.org To: Douglas Anderson Cc: Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Sam Ravnborg , linux-arm-msm@vger.kernel.org, Linus W , Lyude Paul , Bjorn Andersson , Steev Klimaszewski , robdclark@chromium.org, Maarten Lankhorst , Thierry Reding , dri-devel@lists.freedesktop.org, Stanislav Lisovskiy , Stephen Boyd , Daniel Vetter , David Airlie , Thierry Reding , linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 07/11] drm/panel: panel-simple: Stash DP AUX bus; allow using it for DDC In-Reply-To: <20210524165920.v8.7.I18e60221f6d048d14d6c50a770b15f356fa75092@changeid> References: <20210525000159.3384921-1-dianders@chromium.org> <20210524165920.v8.7.I18e60221f6d048d14d6c50a770b15f356fa75092@changeid> Message-ID: <6e0cd667a8a776e524b42f1535827208@codeaurora.org> X-Sender: rajeevny@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi Doug, > panel->no_hpd = of_property_read_bool(dev->of_node, "no-hpd"); > if (!panel->no_hpd) { > @@ -708,6 +712,8 @@ static int panel_simple_probe(struct device *dev, > const struct panel_desc *desc) > > if (!panel->ddc) > return -EPROBE_DEFER; > + } else if (aux) { > + panel->ddc = &aux->ddc; > } In panel_simple_probe(), the put_device(&panel->ddc->dev) call is causing issue when the aux->ddc is used to assign panel->ddc It works well when "ddc-i2c-bus" is used to assign panel->ddc static int panel_simple_probe(...) { ... free_ddc: if (panel->ddc) put_device(&panel->ddc->dev); return err; } == Log start == [ 2.393970] ------------[ cut here ]------------ [ 2.398747] kobject: '(null)' ((____ptrval____)): is not initialized, yet kobject_put() is being called. [ 2.408554] WARNING: CPU: 7 PID: 7 at lib/kobject.c:752 kobject_put+0x38/0xe0 ... ... [ 2.528574] Call trace: [ 2.531092] kobject_put+0x38/0xe0 [ 2.534594] put_device+0x20/0x2c [ 2.538002] panel_simple_probe+0x4bc/0x550 [ 2.542300] panel_simple_dp_aux_ep_probe+0x44/0x5c [ 2.547305] dp_aux_ep_probe+0x58/0x80 == Log end == Sincerely, Rajeev