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 7B73DC4828F for ; Thu, 8 Feb 2024 15:56:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C719710E0B1; Thu, 8 Feb 2024 15:56:10 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="NywdskQ3"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id BFB8110E0B1 for ; Thu, 8 Feb 2024 15:56:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707407769; x=1738943769; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version:content-transfer-encoding; bh=lAwzNKO/gag6aJ20qqU1kWN6RLF7uPPEhVquuaSE/MQ=; b=NywdskQ3WCMw8qel9GMEq2BCIVK5I09IqOX3/cGdTdpCXrDsBk6Nc331 Te8BzyLjPiHorlsbZCnAwat67RdozC8r47MDmZbsLkJFKGGjigDMyCi/B J6amQRW44o6Vh4CydvzPCy7V3AOktS0JkUkmE1dpkeRmaXCcDOy6Vfzob QuHi7NeU/cfCjlgOGs2nXu2svuQQ9SiwfHzdsmXNsIIyLap9v0nHGjVjj orErouwHSHUYjytd0TJsSujh8120woimV2SOwXBY8Mprt+mNU75e2R3JL 7jP1X7zwK9g8bOI7g+0UMaTgCLhC/ew8z+hktT76HLKmpcA76s2zHFi43 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10978"; a="1384716" X-IronPort-AV: E=Sophos;i="6.05,254,1701158400"; d="scan'208";a="1384716" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2024 07:56:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,254,1701158400"; d="scan'208";a="1682539" Received: from unknown (HELO localhost) ([10.237.66.162]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2024 07:56:00 -0800 From: Jani Nikula To: Ville Syrjala , intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org Subject: Re: [PATCH] drm/i915/dp: Limit SST link rate to <=8.1Gbps In-Reply-To: <20240208154552.14545-1-ville.syrjala@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240208154552.14545-1-ville.syrjala@linux.intel.com> Date: Thu, 08 Feb 2024 17:55:53 +0200 Message-ID: <87le7var1y.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 08 Feb 2024, Ville Syrjala wrote: > From: Ville Syrj=C3=A4l=C3=A4 > > Limit the link rate to HBR3 or below (<=3D8.1Gbps) in SST mode. > UHBR (10Gbps+) link rates require 128b/132b channel encoding > which we have not yet hooked up into the SST/no-sideband codepaths. > > Cc: stable@vger.kernel.org > Signed-off-by: Ville Syrj=C3=A4l=C3=A4 My bad. I guess this is the smallest most isolated fix for stable. Reviewed-by: Jani Nikula > --- > drivers/gpu/drm/i915/display/intel_dp.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i9= 15/display/intel_dp.c > index ab415f41924d..5045c34a16be 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -2356,6 +2356,9 @@ intel_dp_compute_config_limits(struct intel_dp *int= el_dp, > limits->min_rate =3D intel_dp_common_rate(intel_dp, 0); > limits->max_rate =3D intel_dp_max_link_rate(intel_dp); >=20=20 > + /* FIXME 128b/132b SST support missing */ > + limits->max_rate =3D min(limits->max_rate, 810000); > + > limits->min_lane_count =3D 1; > limits->max_lane_count =3D intel_dp_max_lane_count(intel_dp); --=20 Jani Nikula, Intel