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=-8.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 15441C433E1 for ; Mon, 24 Aug 2020 18:04:44 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E75A420702 for ; Mon, 24 Aug 2020 18:04:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E75A420702 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 50A6B6E428; Mon, 24 Aug 2020 18:04:43 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 128E66E428 for ; Mon, 24 Aug 2020 18:04:42 +0000 (UTC) IronPort-SDR: OAHtWAF+yr78+Bv2bFVSq93c1d4aa6uUs8h4PGsXAzCp56zxvfGjqAhfh3krPF6iSRvFmQZuoD B/nLedBRmE2g== X-IronPort-AV: E=McAfee;i="6000,8403,9723"; a="157016088" X-IronPort-AV: E=Sophos;i="5.76,349,1592895600"; d="scan'208";a="157016088" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2020 11:04:41 -0700 IronPort-SDR: LaPzsUVRKsJAjxQTXGLpnz9bcVE2WfRx/LmUZnP6AVdLKNQlZ0fhliD0KnuniXJ9Mo3ZfSSegI rI2dWLSvUcqw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,349,1592895600"; d="scan'208";a="298806113" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga006.jf.intel.com with SMTP; 24 Aug 2020 11:04:38 -0700 Received: by stinkbox (sSMTP sendmail emulation); Mon, 24 Aug 2020 21:04:38 +0300 Date: Mon, 24 Aug 2020 21:04:38 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Kai-Heng Feng Message-ID: <20200824180438.GI6112@intel.com> References: <844BC1FA-9C2F-4AAF-A0D9-B9A1EA40F51D@canonical.com> <32B7CFB3-045A-463D-8556-A63BACEB89D1@intel.com> <30685BA7-1D02-48A0-9B7A-4933ED2B8F0D@canonical.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <30685BA7-1D02-48A0-9B7A-4933ED2B8F0D@canonical.com> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [Regression] "drm/i915: Implement display w/a #1143" breaks HDMI on ASUS GL552VW X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx , "Runyan, Arthur J" Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, Aug 17, 2020 at 02:17:49PM +0800, Kai-Heng Feng wrote: > = > = > > On Aug 17, 2020, at 00:22, Runyan, Arthur J = wrote: > > = > > You'll need to read out the DDI_BUF_TRANS_* and DISPIO_CR_TX_BMU_CR0 re= gisters at boot before i915 programs them and compare with what driver prog= rams. = > > Rodrigo can probably show you how. = > = > Right, I'll wait for a patch then :) To grab the BIOS reg values we just have to make sure the driver doesn't load. Eg. pass something like = "modprobe.blacklist=3Di915,snd_hda_intel 3" to the kernel cmdline (+ whatever other magic ubuntu might require). Confirm with something like "lsmod | grep i915" to make sure the driver didn't sneak in despite our best efforts. Then we can dump the registers with intel_reg from igt-gpu-tools: intel_reg read --count 20 0x64E00 0x64E60 0x64EC0 0x64F20 0x64F80 intel_reg read 0x64000 0x64100 0x64200 0x64300 0x64400 0x6C00C The only somewhat suspicious thing I noticed is that we treat DISPIO_CR_TX_BMU_CR0:tx_blnclegdisbl as a bitmask (bit 23 -> DDI A, bit 24 -> DDI B, etc.) whereas the spec seems to be saying that we should just zero out all the bits of tx_blnclegdisbl when any DDI needs iboost. Art, is our interpretation of the bits correct or just a fairy tale? > = > Kai-Heng > = > > = > > -----Original Message----- > > From: Kai-Heng Feng = > > Sent: Thursday, August 13, 2020 10:14 PM > > To: Runyan, Arthur J > > Cc: Vivi, Rodrigo ; Ville Syrj=E4l=E4 ; intel-gfx > > Subject: Re: [Regression] "drm/i915: Implement display w/a #1143" break= s HDMI on ASUS GL552VW > > = > > Hi, > > = > >> On Aug 14, 2020, at 01:56, Runyan, Arthur J wrote: > >> = > >> The workaround is freeing up stuck vswing values to let new vswing pro= gramming kick in. Maybe the new vswing values are wrong. > >> Try checking the vswing that driver programs against what BIOS/GOP pro= grams. > > = > > Do you mean to print out value of I915_READ()? > > val =3D I915_READ(CHICKEN_TRANS(transcoder)); > > = > > Kai-Heng > > = > >> = > >> -----Original Message----- > >> From: Vivi, Rodrigo > >> Sent: Thursday, August 13, 2020 9:50 AM > >> To: Kai-Heng Feng ; Runyan, Arthur J = > >> > >> Cc: Ville Syrj=E4l=E4 ; intel-gfx = > >> > >> Subject: Re: [Regression] "drm/i915: Implement display w/a #1143" = > >> breaks HDMI on ASUS GL552VW > >> = > >> Art, any comment here? > >> = > >> I just checked and the W/a 1143 is implemented as described, but it i= s failing HDMI on this hybrid system. > >> = > >>> On Aug 12, 2020, at 9:07 PM, Kai-Heng Feng wrote: > >>> = > >>> Hi, > >>> = > >>> There's a regression reported that HDMI output stops working after os= upgrade: > >>> https://bugs.launchpad.net/bugs/1871721 > >>> = > >>> Here's the bisect result: > >>> 0519c102f5285476d7868a387bdb6c58385e4074 is the first bad commit = > >>> commit 0519c102f5285476d7868a387bdb6c58385e4074 > >>> Author: Ville Syrj=E4l=E4 > >>> Date: Mon Jan 22 19:41:31 2018 +0200 > >>> = > >>> drm/i915: Implement display w/a #1143 > >>> = > >>> Apparently SKL/KBL/CFL need some manual help to get the > >>> programmed HDMI vswing to stick. Implement the relevant > >>> workaround (display w/a #1143). > >>> = > >>> Note that the relevant chicken bits live in a transcoder register > >>> even though the bits affect a specific DDI port rather than a > >>> specific transcoder. Hence we must pick the correct transcoder > >>> register instance based on the port rather than based on the > >>> cpu_transcoder. > >>> = > >>> Also note that for completeness I included support for DDI A/E > >>> in the code even though we never have HDMI on those ports. > >>> = > >>> v2: CFL needs the w/a as well (Rodrigo and Art) > >>> = > >>> Cc: Rodrigo Vivi > >>> Cc: Art Runyan > >>> Signed-off-by: Ville Syrj=E4l=E4 > >>> Link: https://patchwork.freedesktop.org/patch/msgid/20180122174131.2= 8046-1-ville.syrjala@linux.intel.com > >>> Reviewed-by: Rodrigo Vivi > >>> = > >>> = > >>> dmesg from drm-tip with drm.debug=3D0xe can be found here: > >>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments > >>> / > >>> 64 > >>> = > >>> Kai-Heng > >> = > >> = > > = -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx