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=-7.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 C3966C282CE for ; Mon, 11 Feb 2019 12:55:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94D2D218D8 for ; Mon, 11 Feb 2019 12:55:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=tomli.me header.i=@tomli.me header.b="rs9s1uGT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727281AbfBKMzW (ORCPT ); Mon, 11 Feb 2019 07:55:22 -0500 Received: from tomli.me ([153.92.126.73]:57836 "EHLO tomli.me" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727106AbfBKMzW (ORCPT ); Mon, 11 Feb 2019 07:55:22 -0500 Received: from tomli.me (localhost [127.0.0.1]) by tomli.me (OpenSMTPD) with ESMTP id c32b2060; Mon, 11 Feb 2019 12:55:19 +0000 (UTC) X-HELO: localhost.localdomain Authentication-Results: tomli.me; auth=pass (login) smtp.auth=tomli Received: from Unknown (HELO localhost.localdomain) (2402:f000:1:1501:200:5efe:7b76:76e8) by tomli.me (qpsmtpd/0.95) with ESMTPSA (DHE-RSA-CHACHA20-POLY1305 encrypted); Mon, 11 Feb 2019 12:55:18 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=tomli.me; h=date:from:to:cc:subject:message-id:references:mime-version:content-type:in-reply-to; s=1490979754; bh=xX4ptvedZCTccKySMZWrF9P94x6VEW/wbqt3obLEj8U=; b=rs9s1uGToUcPYKWens3Ti+EWllEAVY4q5MLoupc2IgO9tETBvmo1OSyZhpV+iEsoPRRZbvOHGo98g2Kqc+smBek00+5dvV9NtXzUgofHtsLAU8kjUbxSV0Vf8vs7qe77aZTsSznqf2XoLSoilpWLhChLKp5VBpWh9r7faunjBWpsgTW41bnAMm8MMgaerN+tbvxdEp+N9J5b9xw7K6dddNnAIpxJotu91EGV/auQkaVoHcq1bOBAfBd861O89KGUpZ7ncewrpgbfxPH9wL/wVWXmvo2ZIEw4krfwgD24Lnjjw8XZN4wGT27GdX7Hsty/WBinC01EFRv9Dgai+wgOPw== Date: Mon, 11 Feb 2019 20:55:09 +0800 From: Tom Li To: Alexandre Oliva Cc: James Hogan , Jiaxun Yang , Huacai Chen , Ralf Baechle , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] On the Current Troubles of Mainlining Loongson Platform Drivers Message-ID: <20190211125506.GA21280@localhost.localdomain> References: <20190208083038.GA1433@localhost.localdomain> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="UlVJffcvxoiEqYs2" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org --UlVJffcvxoiEqYs2 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 11, 2019 at 10:13:00AM -0200, Alexandre Oliva wrote: > On Feb 8, 2019, Tom Li wrote: >=20 > > found Alexandre Oliva has stopped maintaining his tree >=20 > ?!? >=20 > I still merge and tag every one of Torvalds' and Greg KH's releases into > the loongson-community tree, resolving trivial conflicts and trying to > verify that it at least builds and passes a smoke test on actual > hardware (after Linux-libre deblobbing, but still). What is the current link to your repository? The original one from Lemote is now a 404, and the GitHub one has been "archived". > Two issues that bother me a bit are frequent failure to reboot/poweroff, > that's been around since around 4.10, and, more recently, a very slow > system overall, that's been present since 4.20. I haven't checked > whether they're caused by changes in the loongson-community tree that I > still carry, or if they're already present in upstream releases. >=20 > I've already tried to bisect the former, but since the issue is > intermittent, that proved to be too tricky and time-consuming for me. >=20 > I haven't tried to bisect the latter yet. You cannot bisect it. Because I've tried it for 24 hours without sleep, but failed. ;-) We've just identified and confirmed the source of the shutdown problem a few days ago on this mailing list. It's related to a PREEMPT race condition in the cpufreq framework that triggers a timing-dependent, probabilistic lockup in the i8259 PIC driver. And it was first noticed by Ville Syrj=E4l= =E4 on a x86 system, my debugging rediscovered his findings. You can read the full investigation at here: https://lkml.org/lkml/2018/11/13/857 You can pick up the patch from: https://lore.kernel.org/lkml/20190207205812.GA11315@darkstar.musicnaut.iki.= fi/ A patch has been authored and submitted by Aaro Koskinen, but currently it seems stuck in the mailing list because the maintainer worries about regres= sion and asks for testing on more MIPS systems, although we believe it's a trivi= al patch. In addition, I've discovered and fixed another bug preventing the machine f= rom shutting down, this patch has already merged into the Linus tree. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?= id=3D8a96669d77897ff3613157bf43f875739205d66d > and, more recently, a very slow system overall, that's been present since > 4.20. The mainline framebuffer driver doesn't have any hardware drawing, printing even a single line on the console is required a full screen redraw via memo= ry- mapped I/O over the slow PCI interface. I have rebased the 2D acceleration code against the latest upstream driver and sent the patch to the fbdev mai= ling list on February 2nd.=20 But the maintainers seem to be working on other tasks and the patches (incl= uding mine and others') on the list didn't receive any response. It's avaliable from https://patchwork.kernel.org/project/linux-fbdev/list/?series=3D75029 > I've considered leaving the loongson-community tree behind and using > upstream releases, but every time I was about to do that, something else > came up that led me to keep at it. I think the last such occurrence was > the removal of the video driver (later reintroduced as a new driver). > So I've kept at it ;-) I'll continue working on upstreaming these out-of-tree drivers as my person= al project. I hope you'll be able to use a fully-functional machine with the m= ainline kernel soon, my current target is Linux 5.3. Cheers, Tom Li --UlVJffcvxoiEqYs2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEJVIRsjlaWj4OSKDx+tPrBeiOjW0FAlxhcKMACgkQ+tPrBeiO jW3ZzhAAiz0joTss55XZrxTd0+nTWkFKZ05FdDccvDsiqi6MPhF4YPkKM8hWX2V4 qkSRtH6GM45QnrbTC3tzb2qjEQM8qNB3j/PPNNr8Lsg9eF0gYQZNN+AqbO48K7Gv /hZyk5vRqv2jYOibkFXqBFb8IQp6I4qHfx6D9SjmVZMVV0f+PrtX+M6hCmHjAclZ On4KjhffuZ3QPxHbMTcDdGebGOG3/eGHi/ra+9OuksJbPCttv7y8fhaS9uQuBhxR CdB/1OUeabT5jb7WzAg5Hx7UFRCqAFeMay98VIk4xoGDOk4HC8g7n0Y3Wcwk6TWg fZJEBqB4N6NyRZ2/OUEYDptFfT7nkF5ddWBpDbUB5Ph9JP8zP3qYG4iysF4IzabY 0yfpvYcCkqPfWeJ1sFl/N6ca3w2OfX1L1DIN++nmmorX05f1dlYzwqPY/kGzJKvn 9CAdtkjsKtkp4OsXhDE2JjM6UeWzp8dBY+PQm5OY0XoPc4GheJGbJYBKgLWcFQm4 EH8hbcGeXwKsQkK2oBDk+zByGWZVZDnBM13exLe9Tahf0KN3Ka+arFgt9nMNvJ1c zcNPJArhxp2h9QxYfTqB2tpous+9x/PGcb6bNeQvPwK8IJO+jJY+2hDHEa/Eieo6 lR8QkHvP29agk0aWizSsI5hifTM4AX6AW3VcZUL3DnVzFJ7s28c= =dCmE -----END PGP SIGNATURE----- --UlVJffcvxoiEqYs2--