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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 AF516C2BA1A for ; Mon, 6 Apr 2020 19:50:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B42120672 for ; Mon, 6 Apr 2020 19:50:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=poorly.run header.i=@poorly.run header.b="B9FOaVqT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726352AbgDFTuv (ORCPT ); Mon, 6 Apr 2020 15:50:51 -0400 Received: from mail-io1-f65.google.com ([209.85.166.65]:45335 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbgDFTuv (ORCPT ); Mon, 6 Apr 2020 15:50:51 -0400 Received: by mail-io1-f65.google.com with SMTP id y14so743791iol.12 for ; Mon, 06 Apr 2020 12:50:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HN+8QL60vvL9kCpBSbE9fq49Mcbwf74LPWCucZYc7mA=; b=B9FOaVqTO+t9lnVPfMPMz/Adln3AhSPXYXjuqMVQ3reEdfCxDmmY6uzxlRmDiPH9pJ y/bpog3PifuFFOX1unxdC+wSgxSAxj56kYkUzESy4/YbG15eX8wy0tDhPr8aGNZ267T5 xLOAP7aJ2agnjB1jHBkT5gtS5jn/nhEoQ4gm4Vlaw+9f90W8wWKSoi4smRo/G2bEi0b0 Lux6rfQfgad3pDJdYjW2GkRY02XLUJ0C1qjB+XS2zSOILjL5oSDth0o5H/zihn5p4vXv jKWUP0X6U1RFeKResnizqbp70IAmVah6nnucDuP0dDgJP6xHiqKZdcFxxhj121UYu7DT x26Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HN+8QL60vvL9kCpBSbE9fq49Mcbwf74LPWCucZYc7mA=; b=RH95urrFBbWrucyvcJi17tZ7S6KkQvxdl7MgF741Sq8NxIIOG86tVLdyn6E74/T1/6 Xr//SWpmXD1XPECPnT+ZBHnWafO9PlhARpr3bCRDYTj4MhBeqWduKoVwgPNR+CH3VFHy zDRZ+JdqTmesmQZ23ca9BRdizorN/auhufs23WwndekXbcTMZTnLALV8wsbiWoclGVdq /7sWLb4LJndMbFp2CtSQNIKR649BloiGKtTrmZP38uIj1Jt9Yp/bStNDXaHlSV4fUMTW iACVQC6T5WLaKSQEgmmlFOqLzPPKhflArkclD0lG4rClyQDEq3+qbA8+ua+359TgVtpq Am3A== X-Gm-Message-State: AGi0PuYJWNrF3BEcNdk5E6x/U3owC194J0J15Ie8W6LM8NomBMrxpkm0 iK+E1D+WPZsZOND06QPwa0adtnZ9Q4u9L9+l3mrF1Q== X-Google-Smtp-Source: APiQypKcSpO3QRsQOcCPdXSdBaq/JteC6JrsZevb7ueYZYqdRIjuhPUpPJUYg/2yI4JWNu2eYOisAC4GmAbJerXl2qY= X-Received: by 2002:a02:cce2:: with SMTP id l2mr960339jaq.83.1586202650623; Mon, 06 Apr 2020 12:50:50 -0700 (PDT) MIME-Version: 1.0 References: <20200403200325.885628-1-lyude@redhat.com> In-Reply-To: <20200403200325.885628-1-lyude@redhat.com> From: Sean Paul Date: Mon, 6 Apr 2020 15:50:14 -0400 Message-ID: Subject: Re: [PATCH] drm/dp_mst: Don't drop NAKs for down responses To: Lyude Paul Cc: dri-devel , Wayne Lin , Wayne Lin , Sean Paul , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 3, 2020 at 4:03 PM Lyude Paul wrote: > > It looks like that when we introduced the ability to handle multiple > down requests at once, we accidentally started dropping NAK replies - > causing sideband messages which got NAK'd to seemingly timeout and cause > all sorts of weirdness. > > So, fix this by making sure we don't return from > drm_dp_mst_handle_down_rep() early, but instead treat NAKs like any > other message. > > Signed-off-by: Lyude Paul > Fixes: fbc821c4a506 ("drm/mst: Support simultaneous down replies") > Cc: Wayne Lin > Cc: Wayne Lin > Cc: Sean Paul Thank you for fixing this Reviewed-by: Sean Paul > --- > drivers/gpu/drm/drm_dp_mst_topology.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c > index 10d0315af513..5449ada3e019 100644 > --- a/drivers/gpu/drm/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > @@ -3813,7 +3813,6 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) > txmsg->reply.u.nak.reason, > drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), > txmsg->reply.u.nak.nak_data); > - goto out_clear_reply; > } > > memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); > -- > 2.25.1 >