From patchwork Tue Dec 19 05:26:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dhinakaran Pandiyan X-Patchwork-Id: 10122289 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 BEF2E6019C for ; Tue, 19 Dec 2017 05:28:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B0CDC28C09 for ; Tue, 19 Dec 2017 05:28:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A5DBD28C40; Tue, 19 Dec 2017 05:28:25 +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=unavailable 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 6E00F28C09 for ; Tue, 19 Dec 2017 05:28:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 00B916E269; Tue, 19 Dec 2017 05:27:58 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5E3CA89A44; Tue, 19 Dec 2017 05:27:44 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Dec 2017 21:27:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,425,1508828400"; d="scan'208";a="3514462" Received: from dk-thinkpad-x260.jf.intel.com (HELO localhost.localdomain) ([10.54.75.18]) by fmsmga007.fm.intel.com with ESMTP; 18 Dec 2017 21:27:24 -0800 From: Dhinakaran Pandiyan To: intel-gfx@lists.freedesktop.org Date: Mon, 18 Dec 2017 21:26:55 -0800 Message-Id: <20171219052659.2355-5-dhinakaran.pandiyan@intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171219052659.2355-1-dhinakaran.pandiyan@intel.com> References: <20171219052659.2355-1-dhinakaran.pandiyan@intel.com> MIME-Version: 1.0 Cc: Daniel Vetter , Dhinakaran Pandiyan , dri-devel@lists.freedesktop.org, Rodrigo Vivi Subject: [Intel-gfx] [PATCH v2 4/8] 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);