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 2273EC48BEB for ; Thu, 15 Feb 2024 15:16:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2E39D10E93E; Thu, 15 Feb 2024 15:16:11 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="hUcMInqF"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 78B4310E93D; Thu, 15 Feb 2024 15:16:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1708010170; x=1739546170; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=rJerO7T+iJlyNznWixSHHFkUOgCtPtAhNcAtt+uTovk=; b=hUcMInqFv9jrTcJ0Gg1vX1IOO6PV9R0z7Z5gCgnD/KRiQUxlB9PAMQQs jxaRSoQgoVMG7o1V2/oPWgCvvB7XUqRCpOv1H64TDemURmQNx31kZnaSy sFiJhr+V6E7PByFrKmRTus2AKcE9OgSFo3Xu6EeLtv6Ux0CulPjEqOCP9 xliN75Vo8qmX9WnPJBqpdWQaDdOpVHt7qS1TwcvnE+IZMCcq0kcCk0pRv /hZab6QSqzuBsdj+/Js2qv+hM/F6YFXKDfomLA7VuwocyYjCoq81pznQ9 GDryPm5Mm45aIIrK4/+pPWaZ0xJeIEJpVlLMfG4TFcwQpR4brrvUCWb/9 A==; X-IronPort-AV: E=McAfee;i="6600,9927,10984"; a="2227183" X-IronPort-AV: E=Sophos;i="6.06,161,1705392000"; d="scan'208";a="2227183" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Feb 2024 07:16:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10984"; a="826424731" X-IronPort-AV: E=Sophos;i="6.06,161,1705392000"; d="scan'208";a="826424731" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by orsmga001.jf.intel.com with SMTP; 15 Feb 2024 07:16:04 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 15 Feb 2024 17:16:03 +0200 Date: Thu, 15 Feb 2024 17:16:03 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jani Nikula Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org, Arun R Murthy Subject: Re: [PATCH v2 2/6] drm/i915/mst: improve debug logging of DP MST mode detect Message-ID: References: <26cddf53e9f7697fc422d19e14bfaf215d6548a6.1707823736.git.jani.nikula@intel.com> <87jzn654rb.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87jzn654rb.fsf@intel.com> X-Patchwork-Hint: comment 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Feb 15, 2024 at 01:46:48PM +0200, Jani Nikula wrote: > On Wed, 14 Feb 2024, Ville Syrjälä wrote: > > On Tue, Feb 13, 2024 at 01:30:57PM +0200, Jani Nikula wrote: > >> Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST > >> detect debug logging there. Debug log the sink's MST capability, > >> including single-stream sideband messaging support, and the decision > >> whether to enable MST mode or not. Do this regardless of whether we're > >> actually enabling MST or not. > >> > >> Cc: Arun R Murthy > >> Cc: Ville Syrjälä > >> Signed-off-by: Jani Nikula > >> --- > >> drivers/gpu/drm/i915/display/intel_dp.c | 45 +++++++++++++++++-------- > >> 1 file changed, 31 insertions(+), 14 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > >> index a1c304f451bd..944f566525dd 100644 > >> --- a/drivers/gpu/drm/i915/display/intel_dp.c > >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c > >> @@ -4007,31 +4007,48 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > >> intel_dp->downstream_ports) == 0; > >> } > >> > >> +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) > >> +{ > >> + if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) > >> + return "single-stream sideband messaging"; > >> + else > >> + return str_yes_no(mst_mode == DRM_DP_MST); > > > > I wonder if this should also just say "sst"/"mst"/"sst sideband" etc. > > Shrug. > > > > Reviewed-by: Ville Syrjälä > > I realize there's an issue here. > > intel_dp_detect_dpcd() bails out early for !drm_dp_is_branch(), before > the intel_dp_can_mst() call. (Renamed intel_dp_mst_detect() here.) > > We'll still happily call intel_dp_configure_mst() later also for > !branch. > > We'll need to call intel_dp_mst_detect() earlier and/or somehow combine > these together. I don't think branch devices need to support MST, but I > think MST devices need to support branching. And single-stream sideband > support does not mean branching. > > The intention of this patch was to improve MST debug logging, but the > end result is that it reduces it! Auch. > > I wonder if we should branch (eh) the detect earlier for eDP, SST and > MST/branch paths. Just to make it easier for our poor brains to follow. Hmm. The sink count check is another case as well. If the device has a local sink, or somehting connected to its DFP(s) it should declare sink count >= 1. -- Ville Syrjälä Intel