From patchwork Wed Dec 14 00:27:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 9473521 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 93BD660762 for ; Wed, 14 Dec 2016 00:28:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 861A8285F8 for ; Wed, 14 Dec 2016 00:28:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7A57E286D7; Wed, 14 Dec 2016 00:28:11 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID 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 117A6285F8 for ; Wed, 14 Dec 2016 00:28:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C19FD6E70A; Wed, 14 Dec 2016 00:27:42 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from galahad.ideasonboard.com (galahad.ideasonboard.com [IPv6:2001:4b98:dc2:45:216:3eff:febb:480d]) by gabe.freedesktop.org (Postfix) with ESMTPS id 18E216E6FE for ; Wed, 14 Dec 2016 00:27:27 +0000 (UTC) Received: from avalon.bb.dnainternet.fi (dfj612ybrt5fhg77mgycy-3.rev.dnainternet.fi [IPv6:2001:14ba:21f5:5b00:2e86:4862:ef6a:2804]) by galahad.ideasonboard.com (Postfix) with ESMTPSA id C482521122; Wed, 14 Dec 2016 01:27:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1481675227; bh=bgI1fxlB1E1lt0I8x8phoNHG6FSRP8YscIiIc/NyR2E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yu+LAipszSfEb6eZlg/bSqdzGWqIs26pSZODiqYmlMmQIr9Zv8JBVT8aJhxh9DFSn pqLGAqrvSXRG3C2LWQzpCsxmDKuOrhCA8VcF9GjhRk8/Xg7T9rtyvV62YG2kJ53yUz WePWY7CYEgA5VjcQApenWi7uScTC1OTQWYc+CzTk= From: Laurent Pinchart To: dri-devel@lists.freedesktop.org Subject: [PATCH v4 13/22] drm: omapdrm: Use a spinlock to protect the CRTC pending flag Date: Wed, 14 Dec 2016 02:27:37 +0200 Message-Id: <1481675266-24598-14-git-send-email-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1481675266-24598-1-git-send-email-laurent.pinchart@ideasonboard.com> References: <1481675266-24598-1-git-send-email-laurent.pinchart@ideasonboard.com> Cc: Tomi Valkeinen X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP The CRTC pending flag will need to be accessed atomically in the vblank interrupt handler, memory barriers won't be enough to protect it. Use a spinlock instead. Signed-off-by: Laurent Pinchart Reviewed-by: Tomi Valkeinen --- Changes since v3: - Reworded commit message --- drivers/gpu/drm/omapdrm/omap_crtc.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c index 7b67ecb02b74..827ac46a6d5e 100644 --- a/drivers/gpu/drm/omapdrm/omap_crtc.c +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c @@ -69,6 +69,19 @@ enum omap_channel omap_crtc_channel(struct drm_crtc *crtc) return omap_crtc->channel; } +static bool omap_crtc_is_pending(struct drm_crtc *crtc) +{ + struct omap_crtc *omap_crtc = to_omap_crtc(crtc); + unsigned long flags; + bool pending; + + spin_lock_irqsave(&crtc->dev->event_lock, flags); + pending = omap_crtc->pending; + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); + + return pending; +} + int omap_crtc_wait_pending(struct drm_crtc *crtc) { struct omap_crtc *omap_crtc = to_omap_crtc(crtc); @@ -78,7 +91,7 @@ int omap_crtc_wait_pending(struct drm_crtc *crtc) * a single frame refresh even on slower displays. */ return wait_event_timeout(omap_crtc->pending_wait, - !omap_crtc->pending, + !omap_crtc_is_pending(crtc), msecs_to_jiffies(250)); } @@ -296,6 +309,7 @@ static void omap_crtc_vblank_irq(struct omap_drm_irq *irq, uint32_t irqstatus) struct omap_crtc *omap_crtc = container_of(irq, struct omap_crtc, vblank_irq); struct drm_device *dev = omap_crtc->base.dev; + struct drm_crtc *crtc = &omap_crtc->base; if (dispc_mgr_go_busy(omap_crtc->channel)) return; @@ -304,10 +318,10 @@ static void omap_crtc_vblank_irq(struct omap_drm_irq *irq, uint32_t irqstatus) __omap_irq_unregister(dev, &omap_crtc->vblank_irq); - rmb(); + spin_lock(&crtc->dev->event_lock); WARN_ON(!omap_crtc->pending); omap_crtc->pending = false; - wmb(); + spin_unlock(&crtc->dev->event_lock); /* wake up userspace */ omap_crtc_complete_page_flip(&omap_crtc->base); @@ -339,10 +353,10 @@ static void omap_crtc_enable(struct drm_crtc *crtc) DBG("%s", omap_crtc->name); - rmb(); + spin_lock_irq(&crtc->dev->event_lock); WARN_ON(omap_crtc->pending); omap_crtc->pending = true; - wmb(); + spin_unlock_irq(&crtc->dev->event_lock); omap_irq_register(crtc->dev, &omap_crtc->vblank_irq); @@ -427,16 +441,13 @@ static void omap_crtc_atomic_flush(struct drm_crtc *crtc, DBG("%s: GO", omap_crtc->name); - rmb(); + spin_lock_irq(&crtc->dev->event_lock); WARN_ON(omap_crtc->pending); omap_crtc->pending = true; - wmb(); - if (crtc->state->event) { - spin_lock_irq(&crtc->dev->event_lock); + if (crtc->state->event) omap_crtc->event = crtc->state->event; - spin_unlock_irq(&crtc->dev->event_lock); - } + spin_unlock_irq(&crtc->dev->event_lock); dispc_mgr_go(omap_crtc->channel); omap_irq_register(crtc->dev, &omap_crtc->vblank_irq);