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 6D188C48BC3 for ; Sat, 17 Feb 2024 15:22:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1E42810E2F6; Sat, 17 Feb 2024 15:22:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="DU23ssNV"; dkim-atps=neutral Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id F373210E069; Sat, 17 Feb 2024 15:22:12 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 18889CE09E6; Sat, 17 Feb 2024 15:22:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32BC7C433F1; Sat, 17 Feb 2024 15:22:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708183330; bh=pnmjMtj6LUKSLk2ge6TNKEdB5HeEr+uuqdYKp1VAbK4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DU23ssNVRNEU/rAOjwOWef06YUBznmP6qaEPZeRmZHrV+pGneYJCIWEwsOnaXllcZ tDfuHD234Qh/hGc/luVN4cqfJwpbk/AYuM/X//gxknluCTgMjU9csI8zjoG7VFd9y+ HSmx8CkAlukSPWwOsN2vvH1E4odRYx94ztQwk2y1wbP7Hr8temgVUKtC9SgaJjAI5B BaG7OFD1ODbbyG3/JXRe+jL1T8vjq3ju4f2V66sndaPIcNTjE2wq6FZGxM2bpbEGnJ ESmQ52WVUFg4ui4nPnUwdmsQBhq6hCY8Xw+XoaCj+wDat6PWn6val5QyD5Sqjh9A8B 1dJdW88kRPXKw== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1rbMW1-000000001dK-0sfA; Sat, 17 Feb 2024 16:22:09 +0100 Date: Sat, 17 Feb 2024 16:22:09 +0100 From: Johan Hovold To: Rob Clark , Abhinav Kumar , Dmitry Baryshkov , Kuogee Hsieh Cc: Sean Paul , Marijn Suijten , David Airlie , Daniel Vetter , Bjorn Andersson , quic_jesszhan@quicinc.com, quic_sbillaka@quicinc.com, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, regressions@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: drm/msm: DisplayPort regressions in 6.8-rc1 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Tue, Feb 13, 2024 at 12:42:17PM +0100, Johan Hovold wrote: > Since 6.8-rc1 the internal eDP display on the Lenovo ThinkPad X13s does > not always show up on boot. > > The logs indicate problems with the runtime PM and eDP rework that went > into 6.8-rc1: > > [ 6.007872] [drm:drm_bridge_attach [drm]] *ERROR* failed to attach bridge /soc@0/phy@88eb000 to encoder TMDS-31: -16 > and this can also manifest itself as a NULL-pointer dereference: > > [ 7.339447] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 > > [ 7.643705] pc : drm_bridge_attach+0x70/0x1a8 [drm] #regzbot ^introduced: 2bcca96abfbf It looks like it may have been possible to hit this also before commit 2bcca96abfbf ("soc: qcom: pmic-glink: switch to DRM_AUX_HPD_BRIDGE") and the transparent bridge rework in 6.8-rc1 even if that has not yet been confirmed. The above is what made this trigger since 6.8-rc1 however. Johan