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 8919CC9830D for ; Wed, 23 Sep 2026 22:21:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 093F010E177; Wed, 23 Sep 2026 22:21:35 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="MQW2YFty"; 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 4A93B10E177; Wed, 23 Sep 2026 22:21:34 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id F412D4023A; Wed, 23 Sep 2026 22:21:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 953501F000FF; Wed, 23 Sep 2026 22:21:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790202093; bh=HnpSOg48K9AyG/QV+c/oO3ibbB0Xil2A4DY+Ahe8o+M=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MQW2YFtyGm+yTls87ESx/JD72pVtNWeslnz22zFvE8TNH++BtsSsMzQk80JbyJ6Kh /lBPi16q9k8u/x3cGI9kvtoztZVdSfqoFMASPnH3umVKaGXkecaZsUtGeGYpivu4j0 2AB2yziTpSBCZZdHQvQf4S6Cw9x3MW4Gy6mAy0lYe6PoiA4aBLf+QnVcok1sZyeR5A qsooyFQsQeW06JYaq7Kj6jsng3e93eNxljzXWmaiolgQeEtTBLfPHMkpWTLa9Bjo/p bstWjUGv/IriXJqo+z8iYr8uOY1y/fqeFfPWLkkIxehnxOQRoF1fgU6dZq5l1uSESp 3i2hEg+yb8K5Q== From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH] drm/i915/dp: Ignore inconsistent TMDS limits on an Anker DP branch To: "Conor Svensson" Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org In-Reply-To: <20260923221018.42133-1-conor10@gmail.com> References: <20260923221018.42133-1-conor10@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 23 Sep 2026 22:21:33 +0000 Message-Id: <20260923222133.953501F000FF@smtp.kernel.org> X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Low] drm/i915/dp: incomplete downstream ports signature match -- commit 025075775ae9b93d6ea2089caff0dfbc102027cd Author: Conor Svensson drm/i915/dp: Ignore inconsistent TMDS limits on an Anker DP branch This commit adds an experimental workaround to clear derived TMDS limits for a specific Anker DP branch device that reports inconsistent capabilities when hotplugged, which can cause the loss of native modes. Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/17180 > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i9= 15/display/intel_dp.c > index 0cd5e6b5034cf..beba989860056 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c [ ... ] > +static bool > +intel_dp_has_anker_tmds_mismatch(struct intel_dp *intel_dp, > + const struct drm_edid *drm_edid) > +{ > + static const struct drm_dp_dpcd_ident branch =3D { > + .oui =3D { 0x90, 0xcc, 0x24 }, > + .device_id =3D { 'S', 'Y', 'N', 'A', 'b', 0x10 }, > + .hw_rev =3D 0x10, > + .sw_major_rev =3D 0x06, > + .sw_minor_rev =3D 0x05, > + }; > + static const u8 downstream_ports[] =3D { > + 0x0a, 0x42, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > + }; [ ... ] > + return !memcmp(&intel_dp->desc.ident, &branch, sizeof(branch)) && > + !memcmp(intel_dp->downstream_ports, downstream_ports, > + sizeof(downstream_ports)) && [Severity: Low] Does this comparison in intel_dp_has_anker_tmds_mismatch() strictly validate the entire downstream port state as intended? Because the local downstream_ports array is defined with only 8 elements, sizeof(downstream_ports) evaluates to 8. However, intel_dp->downstream_ports is a 16-byte array (DP_MAX_DOWNSTREAM_PORTS). This partial match could theoretically trigger the quirk on a different dev= ice that shares the same firmware and first 8 bytes of port capabilities but differs in the remaining 8 bytes, which seems contrary to the deliberately narrow intent described in the commit message. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260923221018.4213= 3-1-conor10@gmail.com?part=3D1