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 X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74673C07E95 for ; Tue, 13 Jul 2021 22:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EA82611AB for ; Tue, 13 Jul 2021 22:25:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236466AbhGMW1y (ORCPT ); Tue, 13 Jul 2021 18:27:54 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:30069 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234665AbhGMW1x (ORCPT ); Tue, 13 Jul 2021 18:27:53 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626215102; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=NrfFoaUg+uge8R5c62DK9xqyU2a37Zv+qz0iccvChbU=; b=jWiDnzpJS4NklBGzmeLN2n9RRkm26vIyWRyxxzlRwjQFogM4iJnmHTd/Pb7yrnSY55bScCJI lN4TipKVxGKdsFOGSCe/NqlpBz9cpAMNcVFr2xHb01kKCogRjGjSrWNEgAzeBlcMbaLIVPLd d2RUFK+9xXuSQWOeoBdVMAhGiFY= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-east-1.postgun.com with SMTP id 60ee12bddc4628fe7e4a26e3 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 13 Jul 2021 22:25:01 GMT Sender: khsieh=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1EA62C433F1; Tue, 13 Jul 2021 22:25:01 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: khsieh) by smtp.codeaurora.org (Postfix) with ESMTPSA id 18AD7C433D3; Tue, 13 Jul 2021 22:24:59 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 13 Jul 2021 15:24:58 -0700 From: khsieh@codeaurora.org To: Jani Nikula Cc: robdclark@gmail.com, sean@poorly.run, swboyd@chromium.org, lyude@redhat.com, abhinavk@codeaurora.org, aravindh@codeaurora.org, rsubbia@codeaurora.org, rnayak@codeaurora.org, freedreno@lists.freedesktop.org, airlied@linux.ie, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] drm/dp_mst: Fix return code on sideband message failure In-Reply-To: <87zguy7c5a.fsf@intel.com> References: <1625585434-9562-1-git-send-email-khsieh@codeaurora.org> <87zguy7c5a.fsf@intel.com> Message-ID: X-Sender: khsieh@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-07-07 01:37, Jani Nikula wrote: > On Tue, 06 Jul 2021, Kuogee Hsieh wrote: >> From: Rajkumar Subbiah >> >> Commit 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing + >> selftests") added some debug code for sideband message tracing. But >> it seems to have unintentionally changed the behavior on sideband >> message >> failure. It catches and returns failure only if DRM_UT_DP is enabled. >> Otherwise it ignores the error code and returns success. So on an MST >> unplug, the caller is unaware that the clear payload message failed >> and >> ends up waiting for 4 seconds for the response. Fixes the issue by >> returning the proper error code. >> >> Changes in V2: >> -- Revise commit text as review comment >> -- add Fixes text >> >> Changes in V3: >> -- remove "unlikely" optimization >> >> Fixes: 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing + >> selftests") >> >> Signed-off-by: Rajkumar Subbiah >> Signed-off-by: Kuogee Hsieh >> >> Reviewed-by: Stephen Boyd > > Reviewed-by: Jani Nikula > > >> --- Lyude, Any comments from you? Thanks, >> drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c >> b/drivers/gpu/drm/drm_dp_mst_topology.c >> index 1590144..df91110 100644 >> --- a/drivers/gpu/drm/drm_dp_mst_topology.c >> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c >> @@ -2887,11 +2887,13 @@ static int process_single_tx_qlock(struct >> drm_dp_mst_topology_mgr *mgr, >> idx += tosend + 1; >> >> ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); >> - if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) { >> - struct drm_printer p = drm_debug_printer(DBG_PREFIX); >> + if (ret) { >> + if (drm_debug_enabled(DRM_UT_DP)) { >> + struct drm_printer p = drm_debug_printer(DBG_PREFIX); >> >> - drm_printf(&p, "sideband msg failed to send\n"); >> - drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); >> + drm_printf(&p, "sideband msg failed to send\n"); >> + drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); >> + } >> return ret; >> }