From patchwork Wed Mar 9 00:29:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 595013 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 7E4D0140C1E; Wed, 9 Mar 2016 23:07:42 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1adctt-0001bF-5r; Wed, 09 Mar 2016 12:07:37 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1adS6M-0000ao-KI for kernel-team@lists.ubuntu.com; Wed, 09 Mar 2016 00:35:46 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1adS6M-0003q9-0a; Wed, 09 Mar 2016 00:35:46 +0000 Received: from kamal by fourier with local (Exim 4.86) (envelope-from ) id 1adS6J-00085R-B9; Tue, 08 Mar 2016 16:35:43 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 120/196] drm: Fix treatment of drm_vblank_offdelay in drm_vblank_on() (v2) Date: Tue, 8 Mar 2016 16:29:38 -0800 Message-Id: <1457483454-30115-121-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457483454-30115-1-git-send-email-kamal@canonical.com> References: <1457483454-30115-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 X-Mailman-Approved-At: Wed, 09 Mar 2016 12:07:33 +0000 Cc: Mario Kleiner , daniel.vetter@ffwll.ch, michel@daenzer.net, Kamal Mostafa , dri-devel@lists.freedesktop.org, vbabka@suse.cz, alexander.deucher@amd.com, Dave Airlie , christian.koenig@amd.com, ville.syrjala@linux.intel.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.19.8-ckt16 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Mario Kleiner commit bb74fc1bf3072bd3ab4ed5f43afd287a63baf2d7 upstream. drm_vblank_offdelay can have three different types of values: < 0 is to be always treated the same as dev->vblank_disable_immediate = 0 is to be treated as "never disable vblanks" > 0 is to be treated as disable immediate if kms driver wants it that way via dev->vblank_disable_immediate. Otherwise it is a disable timeout in msecs. This got broken in Linux 3.18+ for the implementation of drm_vblank_on. If the user specified a value of zero which should always reenable vblank irqs in this function, a kms driver could override the users choice by setting vblank_disable_immediate to true. This patch fixes the regression and keeps the user in control. v2: Only reenable vblank if there are clients left or the user requested to "never disable vblanks" via offdelay 0. Enabling vblanks even in the "delayed disable" case (offdelay > 0) was specifically added by Ville in commit cd19e52aee922 ("drm: Kick start vblank interrupts at drm_vblank_on()"), but after discussion it turns out that this was done by accident. Citing Ville: "I think it just ended up as a mess due to changing some of the semantics of offdelay<0 vs. offdelay==0 vs. disable_immediate during the review of the series. So yeah, given how drm_vblank_put() works now, I'd just make this check for offdelay==0." Signed-off-by: Mario Kleiner Reviewed-by: Daniel Vetter Cc: michel@daenzer.net Cc: vbabka@suse.cz Cc: ville.syrjala@linux.intel.com Cc: daniel.vetter@ffwll.ch Cc: dri-devel@lists.freedesktop.org Cc: alexander.deucher@amd.com Cc: christian.koenig@amd.com Signed-off-by: Dave Airlie Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/drm_irq.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 68193a6..5409518 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1264,8 +1264,7 @@ void drm_vblank_on(struct drm_device *dev, int crtc) * re-enable interrupts if there are users left, or the * user wishes vblank interrupts to be enabled all the time. */ - if (atomic_read(&vblank->refcount) != 0 || - (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0)) + if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0) WARN_ON(drm_vblank_enable(dev, crtc)); spin_unlock_irqrestore(&dev->vbl_lock, irqflags); }