From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: Regression on Chromebook Pixel 2015 due to i915 fastboot always-on Date: Wed, 18 Nov 2015 10:29:00 +0200 Message-ID: <87y4dvd837.fsf@intel.com> References: <564AEC67.8020201@linux.intel.com> <87wpthdky8.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 002376E622 for ; Wed, 18 Nov 2015 00:24:59 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Daniel Vetter , Linus Torvalds Cc: Linux Kernel Mailing List , dri-devel , Dave Airlie , Duncan Laurie List-Id: dri-devel@lists.freedesktop.org T24gVHVlLCAxNyBOb3YgMjAxNSwgRGFuaWVsIFZldHRlciA8ZGFuaWVsLnZldHRlckBmZndsbC5j aD4gd3JvdGU6Cj4gT24gVHVlLCBOb3YgMTcsIDIwMTUgYXQgNzoxOCBQTSwgTGludXMgVG9ydmFs ZHMKPiA8dG9ydmFsZHNAbGludXgtZm91bmRhdGlvbi5vcmc+IHdyb3RlOgo+PiBPbiBUdWUsIE5v diAxNywgMjAxNSBhdCA5OjUzIEFNLCBPbG9mIEpvaGFuc3NvbiA8b2xvZkBsaXhvbS5uZXQ+IHdy b3RlOgo+Pj4KPj4+IFRoZSBwcm9ibGVtIGFzIEkgc2VlIGl0IGlzIHRoYXQgaXQncyB1bmtub3du IGhvdyBtYW55IG1hY2hpbmVzIGRlcGVuZHMKPj4+IG9uIHByZXZpb3VzIGJlaGF2aW9yLiBJZiBp dCdzIG9ubHkgUGl4ZWwgMjAxNSB0aGVuIEkgdGhpbmsgYSB3aGl0ZWxpc3QKPj4+IHdvdWxkIGJl IGp1c3QgZmluZS4KPj4KPj4gQ29uc2lkZXJpbmcgaG93IG1hbnkgcHJvYmxlbXMgd2UgaGlzdG9y aWNhbGx5IGhhdmUgaGFkIHdpdGggYmFja2xpZ2h0Cj4+IGhhbmRsaW5nLCBJIHdvdWxkIHN0cm9u Z2x5IHVyZ2UgcGVvcGxlIHRvICpub3QqIHN0YXJ0IGdvaW5nIGRvd24gdGhlCj4+IHdoaXRlbGlz dCBhcHByb2FjaC4KPj4KPj4gSWYgdGhlIGJhY2tsaWdodCBkb2Vzbid0IGdldCBzZXQgdXAgY29y cmVjdGx5LCB0aGUgbWFjaGluZSBtaWdodCBhcwo+PiB3ZWxsIGJlIGNvbnNpZGVyZWQgZGVhZC4g VmVyeSBmZXcgcGVvcGxlIGFyZSBnb2luZyB0byBnaXZlIGdvb2QKPj4gcmVwb3J0cyBvZiBpdC4g U28gdGhlIGJhY2tsaWdodCBjb2RlIG5lZWRzIHRvIGJlbmQgb2V2ciBiYWNrd2FyZHMgaW4KPj4g YmVpbmcgcm9idXN0IGV2ZW4gbW9yZSBzbyB0aGFuIG1vc3Qgb3RoZXIgY29kZSwgYW5kICJ3aGl0 ZWxpc3QKPj4ga25vd24td29ya2luZyBzZXR1cHMiIGlzIGFic29sdXRlbHkgdGhlIHJldmVyc2Ug b2Ygcm9idXN0LiBJdCdzIGEKPj4gaGFjaywgYW5kIGl0J3MgZ3VhcmFudGVlZCB0byBub3QgYmUg bWFpbnRhaW5hYmxlLgo+Pgo+PiBZZXMsIHllcywgd2UgaGF2ZSB3aGl0ZWxpc3RzIGZvciBvdGhl ciB0aGluZ3MuIEkgaGF0ZSB0aGVtIGluIG90aGVyCj4+IHBsYWNlcyB0b28uIEJ1dCB0aGluZ3Mg bGlrZSAidGhpcyBkZXZpY2UgaGFzIHZlcnkgb2RkIGF1ZGlvCj4+IGNvbmZpZ3VyYXRpb24iIGlz IHZlcnkgZGlmZmVyZW50IGZyb20gInRoaXMgbWFjaGluZSBhcHBlYXJzIGRlYWQgb24KPj4gYm9v dCIsIGZvciBleGFtcGxlLgo+Pgo+PiBTbyByZXZlcnRpbmcgcXVpY2tseSBpcyBkZWZpbml0ZWx5 IHRoZSByaWdodCB0aGluZyB0byBkby4gT3IgYXBwbHlpbmcKPj4gdGhlIHBhdGNoIHRoYXQgYXBw YXJlbnRseSBmaXhlcyBpdCBmb3IgT2xvZiwgYW5kIGhvcGVmdWxseSBmaXhlcyBpdCBpbgo+PiBn ZW5lcmFsIC0gd2l0aG91dCBhbnkga2luZCBvZiByYW5kb20gIm9uIF90aGlzXyBtYWNoaW5lIHdl IGRvIF90aGF0XyIKPj4gY3JhcC4KPj4KPj4gSWYgZHJtIHBlb3BsZSBkb24ndCB3YW50IHRoZSBy ZXZlcnQsIHNlbmQgbWUgYSBwdWxsIHJlcXVlc3Qgd2l0aCB0aGUgZml4Lgo+Cj4gSW1vIHJldmVy dC4gV2l0aCBhbGwgdGhlIFFBIGF3b2wgZmFpbCB3ZSd2ZSBzdWZmZXJlZCB0aGUgcGFzdCBmZXcK PiBtb250aHMgd2UndmUgYmVjb21lIGEgYml0IHRvbyBsYXggaW1vIHdpdGggcmV2ZXJ0aW5nIGZh c3QsIGFuZCB0aGUKPiBwb2ludCBvZiB0aGUgc3BsaXQtb3V0IGNvbW1pdCB3YXMgdG8gYWxsb3cg ZXhhY3RseSB0aGF0LgoKQmFzZWQgb24gdGhlIGxvZ3MgZnJvbSBPbG9mLCBsb29rcyBsaWtlIGEg bW9kZXNldCB3b3VsZCBiZSByZXF1aXJlZCB0bwplbmFibGUgYmFja2xpZ2h0LCBpbnN0ZWFkIG9m IGp1c3QgY3JhbmtpbmcgdXAgdGhlIGJyaWdodG5lc3MuIFNvIGFncmVlZApvbiB0aGUgcmV2ZXJ0 LgoKPiBPbiB0b3AgSSBkb24ndCByZWFsbHkgbGlrZSB0aGUgY2FzdGluZyBNYWFydGVuJ3MgY3Vy cmVudCBoYWNrIGRvZXMsIHdlCj4gcHJvYmFibHkgbmVlZCBhIHBlci1lbmNvZGVyIC0+c2FuaXRp emUgaG9vayBmb3IgdGhpcyBzdHVmZi4gQmV0dGVyIHRvCj4gcmV0cnkgZm9yIDQuNS4gQ2FuIHlv dSBwbHMgcHVzaCB0aGUgcmV2ZXJ0PwoKTW9yZW92ZXIsIHlvdSBjYW4ndCBqdXN0IGVuYWJsZSB0 aGUgYmFja2xpZ2h0IGF0IHdpbGwsIGl0IG5lZWRzIHRvCmZvbGxvdyB0aGUgcGFuZWwgcG93ZXIg c2VxdWVuY2UuIFlvdSBoYXZlIHRvIGVuYWJsZSB0aGUgUFdNIGZpcnN0LCBhbmQKdG9nZ2xlIHRo ZSBwb3dlciBzZXF1ZW5jZXIgYmFja2xpZ2h0IGJpdCBhZnRlciB0aGF0LiBFbmNvZGVyIHNwZWNp ZmljCmhvb2tzIGNhbiBoYW5kbGUgdGhhdC4gVGhvdWdoIG1pZ2h0IHN0aWxsIGJlIHNhZmVzdCB0 byBqdXN0IGZvcmNlIGEKbW9kZXNldCBvbiBtYWNoaW5lcyBpbiB3ZWlyZCBzdGF0ZSBhdCBkcml2 ZXIgbG9hZC4KCkJSLApKYW5pLgoKCi0tIApKYW5pIE5pa3VsYSwgSW50ZWwgT3BlbiBTb3VyY2Ug VGVjaG5vbG9neSBDZW50ZXIKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0 b3Aub3JnCmh0dHA6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmkt ZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755418AbbKRIZF (ORCPT ); Wed, 18 Nov 2015 03:25:05 -0500 Received: from mga11.intel.com ([192.55.52.93]:43382 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755411AbbKRIZA (ORCPT ); Wed, 18 Nov 2015 03:25:00 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,312,1444719600"; d="scan'208";a="853656617" From: Jani Nikula To: Daniel Vetter , Linus Torvalds Cc: Olof Johansson , Maarten Lankhorst , Dave Airlie , Duncan Laurie , dri-devel , Linux Kernel Mailing List Subject: Re: Regression on Chromebook Pixel 2015 due to i915 fastboot always-on In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <564AEC67.8020201@linux.intel.com> <87wpthdky8.fsf@intel.com> User-Agent: Notmuch/0.20.2+101~gb57168b (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Wed, 18 Nov 2015 10:29:00 +0200 Message-ID: <87y4dvd837.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 17 Nov 2015, Daniel Vetter wrote: > On Tue, Nov 17, 2015 at 7:18 PM, Linus Torvalds > wrote: >> On Tue, Nov 17, 2015 at 9:53 AM, Olof Johansson wrote: >>> >>> The problem as I see it is that it's unknown how many machines depends >>> on previous behavior. If it's only Pixel 2015 then I think a whitelist >>> would be just fine. >> >> Considering how many problems we historically have had with backlight >> handling, I would strongly urge people to *not* start going down the >> whitelist approach. >> >> If the backlight doesn't get set up correctly, the machine might as >> well be considered dead. Very few people are going to give good >> reports of it. So the backlight code needs to bend oevr backwards in >> being robust even more so than most other code, and "whitelist >> known-working setups" is absolutely the reverse of robust. It's a >> hack, and it's guaranteed to not be maintainable. >> >> Yes, yes, we have whitelists for other things. I hate them in other >> places too. But things like "this device has very odd audio >> configuration" is very different from "this machine appears dead on >> boot", for example. >> >> So reverting quickly is definitely the right thing to do. Or applying >> the patch that apparently fixes it for Olof, and hopefully fixes it in >> general - without any kind of random "on _this_ machine we do _that_" >> crap. >> >> If drm people don't want the revert, send me a pull request with the fix. > > Imo revert. With all the QA awol fail we've suffered the past few > months we've become a bit too lax imo with reverting fast, and the > point of the split-out commit was to allow exactly that. Based on the logs from Olof, looks like a modeset would be required to enable backlight, instead of just cranking up the brightness. So agreed on the revert. > On top I don't really like the casting Maarten's current hack does, we > probably need a per-encoder ->sanitize hook for this stuff. Better to > retry for 4.5. Can you pls push the revert? Moreover, you can't just enable the backlight at will, it needs to follow the panel power sequence. You have to enable the PWM first, and toggle the power sequencer backlight bit after that. Encoder specific hooks can handle that. Though might still be safest to just force a modeset on machines in weird state at driver load. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center