From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: PROBLEM: Intel VGA output busticated on 4.3-rc2 (regression) Date: Wed, 7 Oct 2015 14:58:50 +0300 Message-ID: <20151007115850.GE26517@intel.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Nick Bowler Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org T24gVHVlLCBPY3QgMDYsIDIwMTUgYXQgMTE6NDI6MzNBTSAtMDQwMCwgTmljayBCb3dsZXIgd3Jv dGU6Cj4gSGksCj4gCj4gVGhpcyBpc3N1ZSBpcyBzdGlsbCBwcmVzZW50IGluIDQuMy1yYzQuCj4g Cj4gT24gOS8yNC8xNSwgTmljayBCb3dsZXIgPG5ib3dsZXJAZHJhY29ueC5jYT4gd3JvdGU6Cj4g PiBUZXN0aW5nIG91dCA0LjMtcmMyLCBmaXJzdCB0aGluZyBJIG5vdGljZSBpcyB0aGF0IHRoZSBW R0Egb3V0cHV0IGlzCj4gPiBub3Qgd29ya2luZy4gIFNwZWNpZmljYWxseSwgdGhlIGRpc3BsYXkg aXMgY29udGludW91c2x5IHBvd2VyaW5nIG9uCj4gPiBhbmQgb2ZmIC0tIGF0IG5vIHBvaW50IGlz IGFueSBpbWFnZSB2aXNpYmxlIG9uIHRoZSBzY3JlZW4gKEkgYW0gZXhwZWN0aW5nCj4gPiB0byBz ZWUgdGhlIGNvbnNvbGUgb3V0cHV0KS4gIFRoZSBkaXNwbGF5IGNvbm5lY3RlZCB0byB0aGUgSERN SSBvdXRwdXQgaXMKPiA+IHdvcmtpbmcgZmluZS4KPiA+Cj4gPiBMaW51eCA0LjIgZGlkIG5vdCBz dWZmZXIgZnJvbSB0aGlzIHByb2JsZW0uCj4gPgo+ID4gSW4gZG1lc2cgSSBzZWUgdGhlIGZvbGxv d2luZyBtZXNzYWdlcywgd2hpY2ggSSBkbyBub3Qgc2VlIG9uIGEgd29ya2luZwo+ID4ga2VybmVs LiAgRnVsbCBkbWVzZyBmcm9tIDQuMy1yYzIgaXMgYXR0YWNoZWQgKGd6aXBwZWQpLgo+ID4KPiA+ ICAgWyAgICAwLjExNTMzOV0gW2RybTpkcm1fY2FsY190aW1lc3RhbXBpbmdfY29uc3RhbnRzXSAq RVJST1IqIGNydGMKPiA+IDIxOiBDYW4ndCBjYWxjdWxhdGUgY29uc3RhbnRzLCBkb3RjbG9jayA9 IDAhCj4gPiAgIFsgICAgMC4xMTc1ODJdIFtkcm06aW50ZWxfb3ByZWdpb25faW5pdF0gKkVSUk9S KiBObyBBQ1BJIHZpZGVvIGJ1cyBmb3VuZAo+ID4KPiA+IFRoaXMgaXMgYW4gb2xkZXIgbWFjaGlu ZSB3aXRoIEludGVsIEc0NSBncmFwaGljcy4KPiAKPiBJIHdhcyBhYmxlIHRvIGlkZW50aWZ5IHRo ZSBjb21taXQgd2hpY2ggZml4ZWQgbXkgYm9vdCBjcmFzaGVzLCBzbyBJCj4gY2hlcnJ5LXBpY2tl ZCA4MGFhOTMxMjg2NTMgKCJkcm0vaTkxNTogZGlzYWJsZV9zaGFyZWRfcGxsIGRvZXNuJ3QKPiB3 b3JrIG9uIHByZS1nZW41Iikgb24gdG9wIG9mIGFsbCBvdGhlcndpc2UgdW50ZXN0YWJsZSBjb21t aXRzLiAgVGhpcwo+IGFsbG93ZWQgYmlzZWN0aW9uIHRvIHByb2NlZWQ6Cj4gCj4gICBiOGFmYjkx MTNjNTE5YThiZDc0MmY3ZGY4YzQyNGIwYWY2OWE3NWNkIGlzIHRoZSBmaXJzdCBiYWQgY29tbWl0 Cj4gICBjb21taXQgYjhhZmI5MTEzYzUxOWE4YmQ3NDJmN2RmOGM0MjRiMGFmNjlhNzVjZAo+ICAg QXV0aG9yOiBWaWxsZSBTeXJqw6Rsw6QgPHZpbGxlLnN5cmphbGFAbGludXguaW50ZWwuY29tPgo+ ICAgRGF0ZTogICBNb24gSnVuIDI5IDE1OjI1OjQ4IDIwMTUgKzAzMDAKPiAKPiAgICAgICBkcm0v aTkxNTogS2VlcCBHTUNIIERQTEwgVkdBIG1vZGUgYWx3YXlzIGRpc2FibGVkCj4gCj4gICAgICAg V2UgZGlzYWJsZSB0aGUgRFBMTCBWR0EgbW9kZSB3aGVuIGVuYWJsaW5nIHRoZSBEUExMLCBidXQg d2UgZW5hYWJsZSBpdAo+ICAgICAgIGFnYWluIHdoZW4gZGlzYWJsaW5nIHRoZSBEUExMLiBIYXZp bmcgVkdBIG1vZGUgZW5hYmxlZCBldmVuIGluIHVudXNlZAo+ICAgICAgIERQTExzIGNhbiBjYXVz ZSBwcm9ibGVtcyBmb3IgQ0hWLCBzbyBpdCBzZWVtcyB3aXNlciB0byBhbHdheXMga2VlcCBpdAo+ ICAgICAgIGRpc2FibGVkLiBBbmQgbGV0J3MganVzdCBkbyB0aGF0IG9uIGFsbCBHTUNIIHBsYXRm b3JtcyB0byBrZWVwIHRoaW5ncwo+ICAgICAgIGFzIHNpbWlsYXIgYXMgcG9zc2libGUgYmV0d2Vl biB0aGVtLgo+IAo+ICAgICAgIFNpZ25lZC1vZmYtYnk6IFZpbGxlIFN5cmrDpGzDpCA8dmlsbGUu c3lyamFsYUBsaW51eC5pbnRlbC5jb20+Cj4gICAgICAgUmV2aWV3ZWQtYnk6IFNpdmFrdW1hciBU aHVsYXNpbWFuaSA8c2l2YWt1bWFyLnRodWxhc2ltYW5pQGludGVsLmNvbT4KPiAgICAgICBTaWdu ZWQtb2ZmLWJ5OiBEYW5pZWwgVmV0dGVyIDxkYW5pZWwudmV0dGVyQGZmd2xsLmNoPgo+IAo+ICAg OjA0MDAwMCAwNDAwMDAgNzc5N2Q1OTZlNzNlY2Y3NTcyMzM3NTAyOGRlY2QyNWZiZTMzMmVlMAo+ IDlmOTBhOTJlZWM0ODM5MTk4NTNkNjg1NjNiYmIwOWE3MWEzMDU1MzIgTQlkcml2ZXJzCj4gCj4g VW5mb3J0dW5hdGVseSBpdCBkb2VzIG5vdCByZXZlcnQgY2xlYW5seSBvbiBtYXN0ZXIuCgpAQCAt MTc5MCwxMyArMTc5MCwxMyBAQCBzdGF0aWMgdm9pZCBpOXh4X2Rpc2FibGVfcGxsKHN0cnVjdCBp bnRlbF9jcnRjICpjcnRjKQogICAgICAgIC8qIE1ha2Ugc3VyZSB0aGUgcGlwZSBpc24ndCBzdGls bCByZWx5aW5nIG9uIHVzICovCiAgICAgICAgYXNzZXJ0X3BpcGVfZGlzYWJsZWQoZGV2X3ByaXYs IHBpcGUpOwogCi0gICAgICAgSTkxNV9XUklURShEUExMKHBpcGUpLCAwKTsKKyAgICAgICBJOTE1 X1dSSVRFKERQTEwocGlwZSksIERQTExfVkdBX01PREVfRElTKTsKICAgICAgICBQT1NUSU5HX1JF QUQoRFBMTChwaXBlKSk7CiB9CgoKVGhhdCBodW5rIGlzIHRoZSBvbmx5IHJlbGV2YW50IHBhcnQg Zm9yIHlvdXIgbWFjaGluZS4gQ2FuIHlvdSB0cnkgdG8gcmV2ZXJ0Cmp1c3QgdGhhdCBtYW51YWxs eT8KCkJ1dCBJJ20gcmVhbGx5IHN1cnByaXNlZCB0aGF0IHdvdWxkIGhhdmUgYW55IGVmZmVjdCBz aW5jZSB3ZSBvbmx5IHVzZWQKdG8gZW5hYmxlICJWR0EgbW9kZSIgd2hlbiB0aGUgRFBMTCBpcyBv ZmYuIEFuZCB3aGVuIHRoZSBEUExMIGlzIG9mZiwKdGhlcmUncyBub3RoaW5nIG9uIHRoZSBzY3Jl ZW4gYW55d2F5LgoKLS0gClZpbGxlIFN5cmrDpGzDpApJbnRlbCBPVEMKX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KSW50ZWwtZ2Z4IG1haWxpbmcgbGlzdApJ bnRlbC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHA6Ly9saXN0cy5mcmVlZGVza3RvcC5v cmcvbWFpbG1hbi9saXN0aW5mby9pbnRlbC1nZngK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753534AbbJGL6z (ORCPT ); Wed, 7 Oct 2015 07:58:55 -0400 Received: from mga01.intel.com ([192.55.52.88]:28918 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752095AbbJGL6y (ORCPT ); Wed, 7 Oct 2015 07:58:54 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,648,1437462000"; d="scan'208";a="821250301" Date: Wed, 7 Oct 2015 14:58:50 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Nick Bowler Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: Re: PROBLEM: Intel VGA output busticated on 4.3-rc2 (regression) Message-ID: <20151007115850.GE26517@intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 06, 2015 at 11:42:33AM -0400, Nick Bowler wrote: > Hi, > > This issue is still present in 4.3-rc4. > > On 9/24/15, Nick Bowler wrote: > > Testing out 4.3-rc2, first thing I notice is that the VGA output is > > not working. Specifically, the display is continuously powering on > > and off -- at no point is any image visible on the screen (I am expecting > > to see the console output). The display connected to the HDMI output is > > working fine. > > > > Linux 4.2 did not suffer from this problem. > > > > In dmesg I see the following messages, which I do not see on a working > > kernel. Full dmesg from 4.3-rc2 is attached (gzipped). > > > > [ 0.115339] [drm:drm_calc_timestamping_constants] *ERROR* crtc > > 21: Can't calculate constants, dotclock = 0! > > [ 0.117582] [drm:intel_opregion_init] *ERROR* No ACPI video bus found > > > > This is an older machine with Intel G45 graphics. > > I was able to identify the commit which fixed my boot crashes, so I > cherry-picked 80aa93128653 ("drm/i915: disable_shared_pll doesn't > work on pre-gen5") on top of all otherwise untestable commits. This > allowed bisection to proceed: > > b8afb9113c519a8bd742f7df8c424b0af69a75cd is the first bad commit > commit b8afb9113c519a8bd742f7df8c424b0af69a75cd > Author: Ville Syrjälä > Date: Mon Jun 29 15:25:48 2015 +0300 > > drm/i915: Keep GMCH DPLL VGA mode always disabled > > We disable the DPLL VGA mode when enabling the DPLL, but we enaable it > again when disabling the DPLL. Having VGA mode enabled even in unused > DPLLs can cause problems for CHV, so it seems wiser to always keep it > disabled. And let's just do that on all GMCH platforms to keep things > as similar as possible between them. > > Signed-off-by: Ville Syrjälä > Reviewed-by: Sivakumar Thulasimani > Signed-off-by: Daniel Vetter > > :040000 040000 7797d596e73ecf75723375028decd25fbe332ee0 > 9f90a92eec483919853d68563bbb09a71a305532 M drivers > > Unfortunately it does not revert cleanly on master. @@ -1790,13 +1790,13 @@ static void i9xx_disable_pll(struct intel_crtc *crtc) /* Make sure the pipe isn't still relying on us */ assert_pipe_disabled(dev_priv, pipe); - I915_WRITE(DPLL(pipe), 0); + I915_WRITE(DPLL(pipe), DPLL_VGA_MODE_DIS); POSTING_READ(DPLL(pipe)); } That hunk is the only relevant part for your machine. Can you try to revert just that manually? But I'm really surprised that would have any effect since we only used to enable "VGA mode" when the DPLL is off. And when the DPLL is off, there's nothing on the screen anyway. -- Ville Syrjälä Intel OTC