From patchwork Thu Oct 20 15:05:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 9387223 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 76C3060762 for ; Thu, 20 Oct 2016 15:24:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6500D29CC1 for ; Thu, 20 Oct 2016 15:24:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 59CF029CC3; Thu, 20 Oct 2016 15:24:43 +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 CD37929CC1 for ; Thu, 20 Oct 2016 15:24:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E097B6EBB3; Thu, 20 Oct 2016 15:24:22 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 397E16EBB6 for ; Thu, 20 Oct 2016 15:24:03 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 40FACABFC; Thu, 20 Oct 2016 15:05:33 +0000 (UTC) From: Takashi Iwai To: dri-devel@lists.freedesktop.org Subject: [PATCH v2] drm/fb-helper: Don't call dirty callback for untouched clips Date: Thu, 20 Oct 2016 17:05:30 +0200 Message-Id: <20161020150530.5787-1-tiwai@suse.de> X-Mailer: git-send-email 2.10.1 Cc: linux-kernel@vger.kernel.org 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 Since 4.7 kernel, we've seen the error messages like kernel: [TTM] Buffer eviction failed kernel: qxl 0000:00:02.0: object_init failed for (4026540032, 0x00000001) kernel: [drm:qxl_alloc_bo_reserved [qxl]] *ERROR* failed to allocate VRAM BO on QXL when switching and accessing on VT. The culprit was the generic deferred_io code (qxl driver switched to it since 4.7). There is a race between the dirty clip update and the call of callback. In drm_fb_helper_dirty(), the dirty clip is updated in the spinlock, while it kicks off the update worker outside the spinlock. Meanwhile the update worker clears the dirty clip in the spinlock, too. Thus, when drm_fb_helper_dirty() is called concurrently, schedule_work() is called after the clip is cleared in the first worker call. This patch addresses it by validating the clip before calling the dirty fb callback. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98322 Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1003298 Fixes: eaa434defaca ('drm/fb-helper: Add fb_deferred_io support') Cc: Signed-off-by: Takashi Iwai Reviewed-by: Ville Syrjälä --- v1->v2: simplified the code as suggested by Ville drivers/gpu/drm/drm_fb_helper.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 03414bde1f15..aae7df01864d 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -644,7 +644,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) clip->x2 = clip->y2 = 0; spin_unlock_irqrestore(&helper->dirty_lock, flags); - helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1); + /* call dirty callback only when it has been really touched */ + if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) + helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1); } /**