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 33538C54E76 for ; Mon, 20 Nov 2023 12:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231948AbjKTMx0 (ORCPT ); Mon, 20 Nov 2023 07:53:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231961AbjKTMx0 (ORCPT ); Mon, 20 Nov 2023 07:53:26 -0500 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47438C4 for ; Mon, 20 Nov 2023 04:53:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1700484802; x=1732020802; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version:content-transfer-encoding; bh=KJb8S+ND/xCwsHauLGmPShFjzVHyXNFQ0jySsBZCjlk=; b=ZrBcb1xMIY8dRpVE9waXItyLDB+R55PPfZP8tWn+Ya6lTToFUfgDC8Oj kHp5GG1KJxQM3suOeqkjioJqhKGbjMdan0kPog2NziWshUKxz/VKb0j4f irvceLOMp7wODY3KRaHq9cOTag7ynUqGqUwKa2EIBSwDykF6d6hgsb066 S69X+E+wJHdRewZknNBE7fScsWM9iA7/Q7E0VOpQ1VE6cgjjuLoMLTZ42 GN/6s/fVigkMnyCfMuxYHv1TbchQ9hd5i9ObSbRzGURAkoZQkBDOrk6fI izJJ2ORcKBrQpYno1AjCOYt0hSwyS0UaXcDVB+0L12/bD6J3o54GOZa9P Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10899"; a="371787460" X-IronPort-AV: E=Sophos;i="6.04,213,1695711600"; d="scan'208";a="371787460" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2023 04:53:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10899"; a="716196394" X-IronPort-AV: E=Sophos;i="6.04,213,1695711600"; d="scan'208";a="716196394" Received: from avmoskal-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.40.194]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2023 04:53:20 -0800 From: Jani Nikula To: Ville Syrjala , intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org Subject: Re: [Intel-gfx] [PATCH] drm/i915: Also check for VGA converter in eDP probe In-Reply-To: <20231114142333.15799-1-ville.syrjala@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20231114142333.15799-1-ville.syrjala@linux.intel.com> Date: Mon, 20 Nov 2023 14:53:17 +0200 Message-ID: <87v89woabm.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, 14 Nov 2023, Ville Syrjala wrote: > From: Ville Syrj=C3=A4l=C3=A4 > > Unfortunately even the HPD based detection added in > commit cfe5bdfb27fa ("drm/i915: Check HPD live state during eDP probe") > fails to detect that the VBT's eDP/DDI-A is a ghost on > Asus B360M-A (CFL+CNP). On that board eDP/DDI-A has its HPD > asserted despite nothing being actually connected there :( > The straps/fuses also indicate that the eDP port is present. > > So if one boots with a VGA monitor connected the eDP probe will > mistake the DP->VGA converter hooked to DDI-E for an eDP panel > on DDI-A. > > As a last resort check what kind of DP device we've detected, > and if it looks like a DP->VGA converter then conclude that > the eDP port should be ignored. > > Cc: stable@vger.kernel.org > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9636 > Fixes: cfe5bdfb27fa ("drm/i915: Check HPD live state during eDP probe") > Signed-off-by: Ville Syrj=C3=A4l=C3=A4 Fingers crossed. Reviewed-by: Jani Nikula > --- > drivers/gpu/drm/i915/display/intel_dp.c | 28 +++++++++++++++++++------ > 1 file changed, 22 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i9= 15/display/intel_dp.c > index 54bd0bffa9f0..14ee05fabd05 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -6277,8 +6277,7 @@ static bool intel_edp_init_connector(struct intel_d= p *intel_dp, > * (eg. Acer Chromebook C710), so we'll check it only if multiple > * ports are attempting to use the same AUX CH, according to VBT. > */ > - if (intel_bios_dp_has_shared_aux_ch(encoder->devdata) && > - !intel_digital_port_connected(encoder)) { > + if (intel_bios_dp_has_shared_aux_ch(encoder->devdata)) { > /* > * If this fails, presume the DPCD answer came > * from some other port using the same AUX CH. > @@ -6286,10 +6285,27 @@ static bool intel_edp_init_connector(struct intel= _dp *intel_dp, > * FIXME maybe cleaner to check this before the > * DPCD read? Would need sort out the VDD handling... > */ > - drm_info(&dev_priv->drm, > - "[ENCODER:%d:%s] HPD is down, disabling eDP\n", > - encoder->base.base.id, encoder->base.name); > - goto out_vdd_off; > + if (!intel_digital_port_connected(encoder)) { > + drm_info(&dev_priv->drm, > + "[ENCODER:%d:%s] HPD is down, disabling eDP\n", > + encoder->base.base.id, encoder->base.name); > + goto out_vdd_off; > + } > + > + /* > + * Unfortunately even the HPD based detection fails on > + * eg. Asus B360M-A (CFL+CNP), so as a last resort fall > + * back to checking for a VGA branch device. Only do this > + * on known affected platforms to minimize false positives. > + */ > + if (DISPLAY_VER(dev_priv) =3D=3D 9 && drm_dp_is_branch(intel_dp->dpcd)= && > + (intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE= _MASK) =3D=3D > + DP_DWN_STRM_PORT_TYPE_ANALOG) { > + drm_info(&dev_priv->drm, > + "[ENCODER:%d:%s] VGA converter detected, disabling eDP\n", > + encoder->base.base.id, encoder->base.name); > + goto out_vdd_off; > + } > } >=20=20 > mutex_lock(&dev_priv->drm.mode_config.mutex); --=20 Jani Nikula, Intel