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 6E566C433EF for ; Tue, 14 Jun 2022 12:58:18 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 51CC410F802; Tue, 14 Jun 2022 12:58:13 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id D38CA10F83F; Tue, 14 Jun 2022 12:58:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655211491; x=1686747491; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=0aXUfNRHFgtqOBcJX+7+alis/BBGRFvAQfSmJxvvsM4=; b=CW2La0BRfYsT0OyAT9+Fyww7jWkdYyHrwGyDuBFYbw/OND9ypoOIyVoA jilab6agkh77Fv7Yd+xBjUIL67czfq7EFmlbJVqNzVYFJQZ8bbvDTPArY Y0gOg0dE8krqp2Pz3Uz4gq9mozcT4m/vYy9JaZzSEDSGu3la6Sd0JXBJh xshE+9P1mLSRfkjAbZ+2g2P7MujlDg8AxKGbFMGDYDt/uTt+ZZt82b3ow adniT7IPHefIKAI6vW4UuL6R5MnjLiIBja98ISEzZdkDqn0LXz/zog4XV gaKZGkGhX0fPwXEfr+18ZtwHsatoH5aBKYJjePu8St50OVIvEgBM8auUz Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10377"; a="261637237" X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="261637237" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 05:58:11 -0700 X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="673861551" Received: from ideak-desk.fi.intel.com ([10.237.72.175]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 05:58:09 -0700 Date: Tue, 14 Jun 2022 15:58:06 +0300 From: Imre Deak To: Jani Nikula Message-ID: References: <20220614094537.885472-1-imre.deak@intel.com> <87sfo7xw5g.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sfo7xw5g.fsf@intel.com> Subject: Re: [Intel-gfx] [PATCH] drm/dp/mst: Read the extended DPCD capabilities during system resume 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: imre.deak@intel.com Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Jun 14, 2022 at 03:32:59PM +0300, Jani Nikula wrote: > On Tue, 14 Jun 2022, Imre Deak wrote: > > The WD22TB4 Thunderbolt dock at least will revert its DP_MAX_LINK_RATE > > from HBR3 to HBR2 after system suspend/resume if the DP_DP13_DPCD_REV > > registers are not read subsequently also as required. > > Does it actually change the behaviour depending on whether the dpcd is > read or not, or is this just about the resume path overwriting mgr->dpcd > with stuff from DP_DPCD_REV? Yes, the reading out DP_DP13_DPCD_REV has a side-effect, see https://gitlab.freedesktop.org/drm/intel/-/issues/5292#note_1343399 > drm_dp_mst_topology_mgr_set_mst() does use drm_dp_read_dpcd_caps() for > reading the caps, which would normally set mgr->dpcd from > DP_DP13_DPCD_REV. Right, but at that point DP_DP13_DPCD_REV returns HBR2 w/o this change. > BR, > Jani. > > > > > Fix this by reading DP_DP13_DPCD_REV registers as well, matching what is > > done during connector detection. While at it also fix up the same call > > in drm_dp_mst_dump_topology(). > > > > Cc: Lyude Paul > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5292 > > Signed-off-by: Imre Deak > > --- > > drivers/gpu/drm/display/drm_dp_mst_topology.c | 7 ++----- > > 1 file changed, 2 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c > > index 67b3b9697da7f..18f2b6075b780 100644 > > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c > > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c > > @@ -3860,9 +3860,7 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, > > if (!mgr->mst_primary) > > goto out_fail; > > > > - ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, > > - DP_RECEIVER_CAP_SIZE); > > - if (ret != DP_RECEIVER_CAP_SIZE) { > > + if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { > > drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); > > goto out_fail; > > } > > @@ -4911,8 +4909,7 @@ void drm_dp_mst_dump_topology(struct seq_file *m, > > u8 buf[DP_PAYLOAD_TABLE_SIZE]; > > int ret; > > > > - ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE); > > - if (ret) { > > + if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { > > seq_printf(m, "dpcd read failed\n"); > > goto out; > > } > > -- > Jani Nikula, Intel Open Source Graphics Center