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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8FB1C77B72 for ; Mon, 17 Apr 2023 11:12:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231196AbjDQLL7 (ORCPT ); Mon, 17 Apr 2023 07:11:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229559AbjDQLL4 (ORCPT ); Mon, 17 Apr 2023 07:11:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D5486585 for ; Mon, 17 Apr 2023 04:11:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BB4616226B for ; Mon, 17 Apr 2023 11:02:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50123C433D2; Mon, 17 Apr 2023 11:02:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681729364; bh=dVSmXgHc7Wtq5f3KTG1Nv3Jo2iMZ9ubzY2vutXfxDvU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=s7eTyOVtBebCEcitRRwiCrhz5ZYaAis5MtzW5zCo7lEaCl418rXJb3cLfzdAMtKxa i1B5/x2H0NA3QcS9YymojTsXU9rZKhmC8orr683S/wEDRRzlMuVJAG1bTRWXAvkgwL qHNfE5OduLyKch7U8X2PBBxVID1zeG05yDokzeFhCfbisdQO1C5uwL/BIsNVF4yz1N UI+5LFtlqy6CAQeW7BfR2ZtzI8p2tD5344rSZ9Qxpk5LaodUuLdBrTgVqlZuuDGnDw meNTzw/SoNRG2F0GABCFHkm3qBSBmoVoUcgUVmsfc0JQmAO4HYZOxB7k181OSFqivW k1n4MKwt4R3HQ== Message-ID: <73d0178c3b9608fae207c9f135aa1f807cb56e47.camel@kernel.org> Subject: Re: [PATCH] drm: make drm_dp_add_payload_part2 gracefully handle NULL state pointer From: Jeff Layton To: Jani Nikula , Lyude Paul , "Lin, Wayne" , Alex Deucher Cc: David Airlie , Daniel Vetter , "Deucher, Alexander" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" Date: Mon, 17 Apr 2023 07:02:41 -0400 In-Reply-To: <87leiqer8g.fsf@intel.com> References: <20230413111254.22458-1-jlayton@kernel.org> <87edooarpq.fsf@intel.com> <4d8479f20ef30866fcf73f3602f1237376110764.camel@kernel.org> <878reug394.fsf@intel.com> <7a1b00f02b125bd65824b18ea09509efe3cf777d.camel@redhat.com> <874jpegao0.fsf@intel.com> <87leiqer8g.fsf@intel.com> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.4 (3.46.4-1.fc37) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2023-04-17 at 13:29 +0300, Jani Nikula wrote: > On Mon, 17 Apr 2023, Jeff Layton wrote: > > On Mon, 2023-04-17 at 11:44 +0300, Jani Nikula wrote: > > > On Fri, 14 Apr 2023, Lyude Paul wrote: > > > > On Fri, 2023-04-14 at 13:35 +0300, Jani Nikula wrote: > > > > > On Fri, 14 Apr 2023, Jeff Layton wrote: > > > > > > On Fri, 2023-04-14 at 04:40 +0000, Lin, Wayne wrote: > > > > > > > [Public] > > > > > > >=20 > > > > > > > Hi Jeff, > > > > > > >=20 > > > > > > > Thanks. I might need more information to understand why we ca= n't retrieve > > > > > > > the drm atomic state. Also , "Failed to create MST payload fo= r port" indicates > > > > > > > error while configuring DPCD payload ID table. Could you help= to provide log > > > > > > > with KMS + ATOMIC + DP debug on please? Thanks in advance! > > > > > > >=20 > > > > > > > Regards, > > > > > > > Wayne > > > > > > >=20 > > > > > >=20 > > > > > > Possibly. I'm not that familiar with display driver debugging. = Can you > > > > > > send me some directions on how to crank up that sort of debug l= ogging? > > > > > >=20 > > > > > > Note that this problem is _very_ intermittent too: I went about= 2 weeks > > > > > > between crashes, and then I got 3 in one day. I'd rather not ru= n with a > > > > > > lot of debug logging for a long time if that's what this is goi= ng to > > > > > > require, as this is my main workstation. > > > > > >=20 > > > > > > The last time I got this log message, my proposed patch did pre= vent the > > > > > > box from oopsing, so I'd really like to see it go in unless it'= s just > > > > > > categorically wrong for the caller to pass down a NULL state po= inter to > > > > > > drm_dp_add_payload_part2. > > > > >=20 > > > > > Cc: Lyude. > > > > >=20 > > > > > Looks like the state parameter was added in commit 4d07b0bc4034 > > > > > ("drm/display/dp_mst: Move all payload info into the atomic state= ") and > > > > > its only use is to get at state->dev for debug logging. > > > > >=20 > > > > > What's the plan for the parameter? Surely something more than tha= t! :) > > > >=20 > > > > I don't think there was any plan for that, or at least I certainly = don't even > > > > remember adding that D:. It must totally have been by mistake and s= nuck by > > > > review, if that's the only thing that we're using it for I'd say it= 's > > > > definitely fine to just drop it entirely > > >=20 > > > I guess we could use two patches then, first replace state->dev with > > > mgr->dev as something that can be backported as needed, and second dr= op > > > the state parameter altogether. > > >=20 > > > Jeff, up for it? At least the first one? > > >=20 > > >=20 > > > BR, > > > Jani. > > >=20 > >=20 > > Sure. I'm happy to test patches if you send them along. >=20 > I was hoping to lure you into sending patches. ;) >=20 > Anyway, I'm not working on this. >=20 >=20 Ok. I misunderstood, I'll change the patch I've been using to use mgr- >dev instead and will send along a v2 here in a few days (after some testing). --=20 Jeff Layton