From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C11369DE6; Sat, 17 Feb 2024 15:22:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708183330; cv=none; b=fMDwNxEyhQ1o2t7anIQe+HqEL4bNNAmnNQsY6T2Uy8WyLUvJ4xuZTmJTu8XCaAFi95sBnxHAD7IyzkDdJH5ehwrIGGu20wVctlu9v+eea6WedfYaKqFg3kD/BHUtGU3vvhbIoqOOcrTAo/8RE5z83tfh93nkPOYyla9nnlpBfvo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708183330; c=relaxed/simple; bh=pnmjMtj6LUKSLk2ge6TNKEdB5HeEr+uuqdYKp1VAbK4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uJ6N4XHCxmzPPh5nbBUcCIqcvDggv1XOpJbOTXMQBaiknBR3YF8qnp+Y5M75z2gW7tOsHCDU7AjgZ/yevnYXpCKBih58zTerph9WdEiTwLS5Q/bmDK76cZj73bjWAxsvqrJ7HQo0KKOxcaibTEZ1sAFzruxOV/l++9+QbrklI48= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DU23ssNV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DU23ssNV" 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: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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