From patchwork Wed Jan 3 20:39:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dhinakaran Pandiyan X-Patchwork-Id: 10143371 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2C8E5601A1 for ; Wed, 3 Jan 2018 20:41:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2011C28E50 for ; Wed, 3 Jan 2018 20:41:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12AD529323; Wed, 3 Jan 2018 20:41:31 +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=-4.2 required=2.0 tests=BAYES_00, 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 7C7D528E50 for ; Wed, 3 Jan 2018 20:41:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 979088919B; Wed, 3 Jan 2018 20:41:28 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id C44DC8919B for ; Wed, 3 Jan 2018 20:41:27 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jan 2018 12:41:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,503,1508828400"; d="scan'208";a="16568743" Received: from dk-thinkpad-x260.jf.intel.com (HELO localhost.localdomain) ([10.54.75.38]) by FMSMGA003.fm.intel.com with ESMTP; 03 Jan 2018 12:41:26 -0800 From: Dhinakaran Pandiyan To: intel-gfx@lists.freedesktop.org Date: Wed, 3 Jan 2018 12:39:57 -0800 Message-Id: <20180103204001.3008-1-dhinakaran.pandiyan@intel.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Cc: Daniel Vetter , Dhinakaran Pandiyan , Rodrigo Vivi Subject: [Intel-gfx] [PATCH 1/5] drm/vblank: Do not update vblank counts if vblanks are already disabled. X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Updating the vblank counts requires register reads and these reads may not return meaningful values after the vblank interrupts are disabled as the device may go to low power state. An additional change would be to allow the driver to save the vblank counts before entering a low power state, but that's for the future. Also, disable vblanks after reading the HW counter in the case where _crtc_vblank_off() is disabling vblanks. Cc: Daniel Vetter Cc: Ville Syrjälä Cc: Rodrigo Vivi Signed-off-by: Dhinakaran Pandiyan --- drivers/gpu/drm/drm_vblank.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 32d9bcf5be7f..7eee82c06ed8 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -347,23 +347,14 @@ void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe) spin_lock_irqsave(&dev->vblank_time_lock, irqflags); /* - * Only disable vblank interrupts if they're enabled. This avoids - * calling the ->disable_vblank() operation in atomic context with the - * hardware potentially runtime suspended. - */ - if (vblank->enabled) { - __disable_vblank(dev, pipe); - vblank->enabled = false; - } - - /* - * Always update the count and timestamp to maintain the + * Update the count and timestamp to maintain the * appearance that the counter has been ticking all along until * this time. This makes the count account for the entire time * between drm_crtc_vblank_on() and drm_crtc_vblank_off(). */ drm_update_vblank_count(dev, pipe, false); - + __disable_vblank(dev, pipe); + vblank->enabled = false; spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); } @@ -1122,8 +1113,12 @@ void drm_crtc_vblank_off(struct drm_crtc *crtc) pipe, vblank->enabled, vblank->inmodeset); /* Avoid redundant vblank disables without previous - * drm_crtc_vblank_on(). */ - if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset) + * drm_crtc_vblank_on() and only disable them if they're enabled. This + * avoids calling the ->disable_vblank() operation in atomic context + * with the hardware potentially runtime suspended. + */ + if ((drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset) && + vblank->enabled) drm_vblank_disable_and_save(dev, pipe); wake_up(&vblank->queue);