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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0C617C43458 for ; Thu, 9 Jul 2026 10:56:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6BA4610F055; Thu, 9 Jul 2026 10:56:00 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="kmB/dkru"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6779D10F055 for ; Thu, 9 Jul 2026 10:55:59 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 04A83413DA; Thu, 9 Jul 2026 10:55:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9096C1F000E9; Thu, 9 Jul 2026 10:55:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783594558; bh=2X1PitPO16swJpGXR4Ylf1gJYaJBEkZV8itpiOkhNzo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=kmB/dkruhVSAUuWPuT4Hniwf/0abzRlbQcvrB2+eOVOyKOBCs0VVOFoWhdNA6TjRs BpWZpfnuGnFiJfRkCU3uqNwZs4+zRj9UH4nh64mWxkm8zrQOPO+L/wfRMxOWkg6EHa hYp+vVjbix2596fhNAZo2SABfZZiOWHmMnOD4ps1FQ9Yqfs+nxkVsMzURIwkGVwgyt wzZ5WwMFtjrtsD+JmA1xWKphevZ0IY1bGoJ5AU/7WjN64NXOfxtXTz4GcQmd3DHhht JvZA7MXhtsPLF8KPPgq2j5GRUg4lvodDNubaD5tPek64NIZV4nbwjQ1lcjsXjSTVKG sTsmFYgAWS/PA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 07/11] drm/mediatek: mtk_dp: Add support for PHY from devicetree To: "AngeloGioacchino Del Regno" Cc: conor+dt@kernel.org, devicetree@vger.kernel.org, robh@kernel.org, dri-devel@lists.freedesktop.org In-Reply-To: <20260709103431.46616-8-angelogioacchino.delregno@collabora.com> References: <20260709103431.46616-1-angelogioacchino.delregno@collabora.com> <20260709103431.46616-8-angelogioacchino.delregno@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 09 Jul 2026 10:55:57 +0000 Message-Id: <20260709105558.9096C1F000E9@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 2 potential issue(= s) to consider: - [High] Double unregister of the PHY platform device in the error path of = `mtk_dp_register_phy()`. - [High] `phy_power_on()` is called before `phy_init()` during eDP probe on= new devicetrees. -- --- Patch [7]: [PATCH v3 07/11] drm/mediatek: mtk_dp: Add support for PHY f= rom devicetree --- commit 325a8fa9ebb5392753c0df0c9aa94be702f67e6e Author: AngeloGioacchino Del Regno drm/mediatek: mtk_dp: Add support for PHY from devicetree This commit adds support for passing a displayport PHY handle from the devicetree. It introduces a check for the phys property to support newer configurations while maintaining legacy fallback behavior. > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek= /mtk_dp.c > index b4cb1996a3314..cabfc833c0a80 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dp.c > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c [ ... ] > @@ -2754,6 +2775,7 @@ static int mtk_dp_register_phy(struct mtk_dp *mtk_d= p) > return dev_err_probe(dev, ret, > "Failed to add phy unregister devm action"); > =20 > + /* PHY calibration data is in mtk_dp only for legacy devicetree */ > mtk_dp_get_calibration_data(mtk_dp); > =20 > mtk_dp->phy =3D devm_phy_get(&mtk_dp->phy_dev->dev, "dp"); [Severity: High] Could this error path trigger a double-free of the PHY platform device? In mtk_dp_register_phy(), we register a devres action to unregister the platform device via mtk_dp_unregister_pdevs(). If devm_phy_get() fails and we return an error (like -EPROBE_DEFER), the explicit call to platform_device_unregister() in the error path will free the device. When the devres cleanup runs later, it will execute mtk_dp_unregister_pdevs() and call platform_device_unregister() a second time on the same pointer. [ ... ] > @@ -2857,9 +2884,18 @@ static int mtk_dp_probe(struct platform_device *pd= ev) > "Failed to register audio driver\n"); > } > =20 > - ret =3D mtk_dp_register_phy(mtk_dp); > - if (ret) > - return ret; > + if (!mtk_dp->legacy_regoff) { > + mtk_dp->phy =3D devm_phy_get(dev, NULL); > + if (IS_ERR(mtk_dp->phy)) > + return dev_err_probe(dev, PTR_ERR(mtk_dp->phy), > + "Failed to get phy\n"); > + > + mtk_dp->phy_dev =3D NULL; [Severity: High] Are we calling phy_power_on() before phy_init() for eDP displays on new devicetrees? During mtk_dp_probe() for eDP connectors, the driver calls mtk_dp_power_enable() to read the EDID before the bridge is attached. With the new PHY model, this executes phy_power_on(mtk_dp->phy): mtk_dp_probe() mtk_dp_power_enable() phy_power_on(mtk_dp->phy); However, phy_init() is not called until mtk_dp_bridge_attach() via mtk_dp_poweron(). Violating the PHY API contract by powering on before initialization can cause hardware initialization failures, as clocks or regulators managed by phy_init() are not yet enabled. > + } else { > + ret =3D mtk_dp_register_phy(mtk_dp); > + if (ret) > + return ret; > + } > =20 > mtk_dp->bridge.of_node =3D dev->of_node; > mtk_dp->bridge.type =3D mtk_dp->data->bridge_type; --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260709103431.4661= 6-1-angelogioacchino.delregno@collabora.com?part=3D7