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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9315C6FA8C for ; Tue, 6 Sep 2022 13:45:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234056AbiIFNpA (ORCPT ); Tue, 6 Sep 2022 09:45:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239662AbiIFNoN (ORCPT ); Tue, 6 Sep 2022 09:44:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1372D7F0AB; Tue, 6 Sep 2022 06:38:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8953861552; Tue, 6 Sep 2022 13:36:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F7F8C433C1; Tue, 6 Sep 2022 13:36:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471392; bh=24Gtr3ZjFh86hio1nJHGtFL8xDc82Ac6doIxTsAnxmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O5mF9Li1YgX0tPYauIcy8Zd3/6xfhdVihcwLlya6dqeCdgp7moxrbOcXD8hoyyxjj wtubCtNSWiSPRPJ5y1TxX3vcAnynDMhPZw1l0KEJvlcvAVj/gENFpflBUesM5XMkhK J7VHGFWbre/gq4eW2CsOUPV4uSRxvX2GVWk/R1w8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arun R Murthy , Jani Nikula , Rodrigo Vivi , Sasha Levin Subject: [PATCH 5.15 012/107] drm/i915/display: avoid warnings when registering dual panel backlight Date: Tue, 6 Sep 2022 15:29:53 +0200 Message-Id: <20220906132822.278140983@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132821.713989422@linuxfoundation.org> References: <20220906132821.713989422@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Arun R Murthy [ Upstream commit 868e8e5156a1f8d92ca83fdbac6fd52798650792 ] Commit 20f85ef89d94 ("drm/i915/backlight: use unique backlight device names") added support for multiple backlight devices on dual panel systems, but did so with error handling on -EEXIST from backlight_device_register(). Unfortunately, that triggered a warning in dmesg all the way down from sysfs_add_file_mode_ns() and sysfs_warn_dup(). Instead of optimistically always attempting to register with the default name ("intel_backlight", which we have to retain for backward compatibility), check if a backlight device with the name exists first, and, if so, use the card and connector based name. v2: reworked on top of the patch commit 20f85ef89d94 ("drm/i915/backlight: use unique backlight device names") v3: fixed the ref count leak(Jani N) Fixes: 20f85ef89d94 ("drm/i915/backlight: use unique backlight device names") Signed-off-by: Arun R Murthy Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20220808035750.3111046-1-arun.r.murthy@intel.com (cherry picked from commit 4234ea30051200fc6016de10e4d58369e60b38f1) Signed-off-by: Rodrigo Vivi Signed-off-by: Sasha Levin --- .../gpu/drm/i915/display/intel_backlight.c | 26 +++++++++---------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index 4b0086ee48519..60f91ac7d1427 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -966,26 +966,24 @@ int intel_backlight_device_register(struct intel_connector *connector) if (!name) return -ENOMEM; - bd = backlight_device_register(name, connector->base.kdev, connector, - &intel_backlight_device_ops, &props); - - /* - * Using the same name independent of the drm device or connector - * prevents registration of multiple backlight devices in the - * driver. However, we need to use the default name for backward - * compatibility. Use unique names for subsequent backlight devices as a - * fallback when the default name already exists. - */ - if (IS_ERR(bd) && PTR_ERR(bd) == -EEXIST) { + bd = backlight_device_get_by_name(name); + if (bd) { + put_device(&bd->dev); + /* + * Using the same name independent of the drm device or connector + * prevents registration of multiple backlight devices in the + * driver. However, we need to use the default name for backward + * compatibility. Use unique names for subsequent backlight devices as a + * fallback when the default name already exists. + */ kfree(name); name = kasprintf(GFP_KERNEL, "card%d-%s-backlight", i915->drm.primary->index, connector->base.name); if (!name) return -ENOMEM; - - bd = backlight_device_register(name, connector->base.kdev, connector, - &intel_backlight_device_ops, &props); } + bd = backlight_device_register(name, connector->base.kdev, connector, + &intel_backlight_device_ops, &props); if (IS_ERR(bd)) { drm_err(&i915->drm, -- 2.35.1