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=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 80870C282C2 for ; Wed, 13 Feb 2019 14:52:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 521CC222C2 for ; Wed, 13 Feb 2019 14:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550069543; bh=J1kTcrjYaadphNOgQ38fDNww560oBIyDXhEaRc4OChc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=a9Bvf0a+YAdFNwINwRgD52bGA7e/9wPY/yOqqCdvCXPItIXqe0m+vyOIfXt9MfIIz VR4pzyGZfKLuYSCLhsEBSvXKSc67sapijbnMBYMjcfcuv4OxNsNEV0g9JMvpQz0WcD q37mcmfP6/x8T1rx6rUWbuf0a/QmD3y/XvC2eOvo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727562AbfBMOwW (ORCPT ); Wed, 13 Feb 2019 09:52:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:40430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726056AbfBMOwW (ORCPT ); Wed, 13 Feb 2019 09:52:22 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7E2A3222C1; Wed, 13 Feb 2019 14:52:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550069542; bh=J1kTcrjYaadphNOgQ38fDNww560oBIyDXhEaRc4OChc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Qyqiewtj3WZHJIBNDrasoX81eyGPA/lrWHhEo4iQou3RTGzWXwUpzV0ImD0vFp9Ue MTpt+3T2UydCvtkW1XTI2gMy/wCgX1sHn4P/4lfW9VfBFzenBznmiClucBGiYWhq2V Nda0CDFmWwk9h4pHTsPwyZzvF4tgAVrb2f/cLSAs= Date: Wed, 13 Feb 2019 15:52:19 +0100 From: Greg KH To: Ville Syrjala Cc: stable@vger.kernel.org, dkk089@gmail.com, jani.nikula@intel.com, mika.kahola@intel.com Subject: Re: [PATCH stable-4.20] drm/i915: Try to sanitize bogus DPLL state left over by broken SNB BIOSen Message-ID: <20190213145219.GA19166@kroah.com> References: <155006608714177@kroah.com> <20190213144734.1344-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190213144734.1344-1-ville.syrjala@linux.intel.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Feb 13, 2019 at 04:47:34PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä > > Certain SNB machines (eg. ASUS K53SV) seem to have a broken BIOS > which misprograms the hardware badly when encountering a suitably > high resolution display. The programmed pipe timings are somewhat > bonkers and the DPLL is totally misprogrammed (P divider == 0). > That will result in atomic commit timeouts as apparently the pipe > is sufficiently stuck to not signal vblank interrupts. > > IIRC something like this was also observed on some other SNB > machine years ago (might have been a Dell XPS 8300) but a BIOS > update cured it. Sadly looks like this was never fixed for the > ASUS K53SV as the latest BIOS (K53SV.320 11/11/2011) is still > broken. > > The quickest way to deal with this seems to be to shut down > the pipe+ports+DPLL. Unfortunately doing this during the > normal sanitization phase isn't quite soon enough as we > already spew several WARNs about the bogus hardware state. > But it's better than hanging the boot for a few dozen seconds. > Since this is limited to a few old machines it doesn't seem > entirely worthwile to try and rework the readout+sanitization > code to handle it more gracefully. > > v2: Fix potential NULL deref (kbuild test robot) > Constify has_bogus_dpll_config() > > Cc: stable@vger.kernel.org # v4.20+ > Cc: Daniel Kamil Kozar > Reported-by: Daniel Kamil Kozar > Tested-by: Daniel Kamil Kozar > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109245 > Fixes: 516a49cc1946 ("drm/i915: Fix assert_plane() warning on bootup with external display") > Signed-off-by: Ville Syrjälä > Link: https://patchwork.freedesktop.org/patch/msgid/20190111174950.10681-1-ville.syrjala@linux.intel.com > Reviewed-by: Mika Kahola > (cherry picked from commit 7bed8adcd9f86231bb69bbc02f88ad89330f99e3) > Signed-off-by: Jani Nikula > Link: https://patchwork.freedesktop.org/patch/msgid/20190205141846.6053-1-ville.syrjala@linux.intel.com > (cherry picked from commit d028a646e84b9b131e4ff2cb5bbdd3825d141028) Now queued up, thanks. greg k-h