From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756660AbcCBATV (ORCPT ); Tue, 1 Mar 2016 19:19:21 -0500 Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:57058 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932373AbcCAX55 (ORCPT ); Tue, 1 Mar 2016 18:57:57 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=mandrill; d=linuxfoundation.org; b=J57YXgbPw8HC9lyEhkCg1oNHjy21bS4k1/SdOlYxpG5UPubucsptNUXaSF7SOSVpLc1NwoLiWE+W DWRrIRzULbKowO/wUhVxqUMXhl8Q2civaKY19lQZ4SEXNwda7qCDBwL6fWAiggNFJiXB4J3RfwyG EzPaWLI2Nh+TehluT6g=; From: Greg Kroah-Hartman Subject: [PATCH 4.4 229/342] drm: No-Op redundant calls to drm_vblank_off() (v2) X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , Mario Kleiner , Daniel Vetter , , , , , , Dave Airlie Message-Id: <20160301234535.326241606@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.96cf9389c92f4647bf27b66204571940 X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:55:16 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mario Kleiner commit e8235891b33799d597ff4ab5e45afe173a65da30 upstream. Otherwise if a kms driver calls into drm_vblank_off() more than once before calling drm_vblank_on() again, the redundant calls to vblank_disable_and_save() will call drm_update_vblank_count() while hw vblank counters and vblank timestamping are in a undefined state during modesets, dpms off etc. At least with the legacy drm helpers it is not unusual to get multiple calls to drm_vblank_off and drm_vblank_on, e.g., half a dozen calls to drm_vblank_off and two calls to drm_vblank_on were observed on radeon-kms during dpms-off -> dpms-on transition. We don't no-op calls from atomic modesetting drivers, as they should do a proper job of tracking hw state. Fixes large jumps of the software maintained vblank counter due to the hardware vblank counter resetting to zero during dpms off or modeset, e.g., if radeon-kms is modified to use drm_vblank_off/on instead of drm_vblank_pre/post_modeset(). This fixes a regression caused by the changes made to drm_update_vblank_count() in Linux 4.4. v2: Don't no-op on atomic modesetting drivers, per suggestion of Daniel Vetter. Signed-off-by: Mario Kleiner Reviewed-by: Daniel Vetter Cc: michel@daenzer.net Cc: vbabka@suse.cz Cc: ville.syrjala@linux.intel.com Cc: alexander.deucher@amd.com Cc: christian.koenig@amd.com Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_irq.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1313,7 +1313,13 @@ void drm_vblank_off(struct drm_device *d spin_lock_irqsave(&dev->event_lock, irqflags); spin_lock(&dev->vbl_lock); - vblank_disable_and_save(dev, pipe); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + + /* Avoid redundant vblank disables without previous drm_vblank_on(). */ + if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset) + vblank_disable_and_save(dev, pipe); + wake_up(&vblank->queue); /* @@ -1415,6 +1421,9 @@ void drm_vblank_on(struct drm_device *de return; spin_lock_irqsave(&dev->vbl_lock, irqflags); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + /* Drop our private "prevent drm_vblank_get" refcount */ if (vblank->inmodeset) { atomic_dec(&vblank->refcount); From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:27939 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932318AbcCAX5u (ORCPT ); Tue, 1 Mar 2016 18:57:50 -0500 Received: from pmta06.mandrill.prod.suw01.rsglab.com (127.0.0.1) by mail177-1.suw61.mandrillapp.com id hqom7q22rtka for ; Tue, 1 Mar 2016 23:55:15 +0000 (envelope-from ) From: Greg Kroah-Hartman Subject: [PATCH 4.4 229/342] drm: No-Op redundant calls to drm_vblank_off() (v2) To: Cc: Greg Kroah-Hartman , , Mario Kleiner , Daniel Vetter , , , , , , Dave Airlie Message-Id: <20160301234535.326241606@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:55:15 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mario Kleiner commit e8235891b33799d597ff4ab5e45afe173a65da30 upstream. Otherwise if a kms driver calls into drm_vblank_off() more than once before calling drm_vblank_on() again, the redundant calls to vblank_disable_and_save() will call drm_update_vblank_count() while hw vblank counters and vblank timestamping are in a undefined state during modesets, dpms off etc. At least with the legacy drm helpers it is not unusual to get multiple calls to drm_vblank_off and drm_vblank_on, e.g., half a dozen calls to drm_vblank_off and two calls to drm_vblank_on were observed on radeon-kms during dpms-off -> dpms-on transition. We don't no-op calls from atomic modesetting drivers, as they should do a proper job of tracking hw state. Fixes large jumps of the software maintained vblank counter due to the hardware vblank counter resetting to zero during dpms off or modeset, e.g., if radeon-kms is modified to use drm_vblank_off/on instead of drm_vblank_pre/post_modeset(). This fixes a regression caused by the changes made to drm_update_vblank_count() in Linux 4.4. v2: Don't no-op on atomic modesetting drivers, per suggestion of Daniel Vetter. Signed-off-by: Mario Kleiner Reviewed-by: Daniel Vetter Cc: michel@daenzer.net Cc: vbabka@suse.cz Cc: ville.syrjala@linux.intel.com Cc: alexander.deucher@amd.com Cc: christian.koenig@amd.com Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_irq.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1313,7 +1313,13 @@ void drm_vblank_off(struct drm_device *d spin_lock_irqsave(&dev->event_lock, irqflags); spin_lock(&dev->vbl_lock); - vblank_disable_and_save(dev, pipe); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + + /* Avoid redundant vblank disables without previous drm_vblank_on(). */ + if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset) + vblank_disable_and_save(dev, pipe); + wake_up(&vblank->queue); /* @@ -1415,6 +1421,9 @@ void drm_vblank_on(struct drm_device *de return; spin_lock_irqsave(&dev->vbl_lock, irqflags); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + /* Drop our private "prevent drm_vblank_get" refcount */ if (vblank->inmodeset) { atomic_dec(&vblank->refcount);