From patchwork Tue Jul 31 00:39:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 10549729 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6B2B5157D for ; Tue, 31 Jul 2018 00:40:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 66BE02A9DF for ; Tue, 31 Jul 2018 00:40:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 647D82AA40; Tue, 31 Jul 2018 00:40:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0E8072A9DF for ; Tue, 31 Jul 2018 00:40:47 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 597C76E255; Tue, 31 Jul 2018 00:40:10 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by gabe.freedesktop.org (Postfix) with ESMTPS id BDEB96E17C; Tue, 31 Jul 2018 00:40:05 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 182287DAC7; Tue, 31 Jul 2018 00:40:05 +0000 (UTC) Received: from malachite.bss.redhat.com (dhcp-10-20-1-11.bss.redhat.com [10.20.1.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id BB86D16875; Tue, 31 Jul 2018 00:40:04 +0000 (UTC) From: Lyude Paul To: nouveau@lists.freedesktop.org Subject: [PATCH v3 4/8] drm/nouveau: Fix deadlock with fb_helper using new helpers Date: Mon, 30 Jul 2018 20:39:49 -0400 Message-Id: <20180731003954.19962-5-lyude@redhat.com> In-Reply-To: <20180731003954.19962-1-lyude@redhat.com> References: <20180731003954.19962-1-lyude@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 31 Jul 2018 00:40:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 31 Jul 2018 00:40:05 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lyude@redhat.com' RCPT:'' X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , Karol Herbst , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Ben Skeggs MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP This removes the potential of deadlocking with fb_helper entirely by preventing it from handling hotplugs during the runtime suspend process as early as possible in the suspend process. If it turns out this is not possible, due to some fb_helper action having been queued up before we got a time to disable hotplugging, we simply return -EBUSY so that the runtime PM core attempts autosuspending the device again once fb_helper isn't doing anything. This fixes one of the issues causing deadlocks on runtime suspend/resume with nouveau on my P50. Signed-off-by: Lyude Paul Cc: stable@vger.kernel.org Cc: Lukas Wunner Cc: Karol Herbst --- drivers/gpu/drm/nouveau/nouveau_drm.c | 8 ++++++++ drivers/gpu/drm/nouveau/nouveau_fbcon.c | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index ee2546db09c9..d47cb5b2af98 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -836,6 +836,14 @@ nouveau_pmops_runtime_suspend(struct device *dev) return -EBUSY; } + /* There's no way for us to stop fb_helper work in reaction to + * hotplugs later in the RPM process. First off: we don't want to, + * fb_helper should be able to keep the GPU awake. Second off: it is + * capable of grabbing basically any lock in existence. + */ + if (!drm_fb_helper_suspend_hotplug(drm_dev->fb_helper)) + return -EBUSY; + nouveau_switcheroo_optimus_dsm(); ret = nouveau_do_suspend(drm_dev, true); pci_save_state(pdev); diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 85c1f10bc2b6..963ba630fd04 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -466,6 +466,7 @@ nouveau_fbcon_set_suspend_work(struct work_struct *work) console_unlock(); if (state == FBINFO_STATE_RUNNING) { + drm_fb_helper_resume_hotplug(drm->dev->fb_helper); pm_runtime_mark_last_busy(drm->dev->dev); pm_runtime_put_sync(drm->dev->dev); }