From patchwork Wed Jan 9 13:47:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Holler X-Patchwork-Id: 1952791 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 6B7AB3FC5A for ; Wed, 9 Jan 2013 13:48:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757847Ab3AINso (ORCPT ); Wed, 9 Jan 2013 08:48:44 -0500 Received: from h1446028.stratoserver.net ([85.214.92.142]:40506 "EHLO mail.ahsoftware.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757805Ab3AINsn (ORCPT ); Wed, 9 Jan 2013 08:48:43 -0500 Received: by mail.ahsoftware.de (Postfix, from userid 65534) id EDF29888B13; Wed, 9 Jan 2013 14:48:41 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.ahsoftware.de X-Spam-Level: X-Spam-Status: No, score=-101.0 required=5.0 tests=ALL_TRUSTED, USER_IN_WHITELIST autolearn=disabled version=3.3.1 Received: from eiche.ahsoftware (p57B20479.dip0.t-ipconnect.de [87.178.4.121]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.ahsoftware.de (Postfix) with ESMTPSA id D5864888132; Wed, 9 Jan 2013 14:48:40 +0100 (CET) Received: by eiche.ahsoftware (Postfix, from userid 65534) id E8CDF3FC83; Wed, 9 Jan 2013 14:48:39 +0100 (CET) Received: from krabat.ahsoftware (unknown [192.168.207.2]) by eiche.ahsoftware (Postfix) with ESMTP id 022323FC83; Wed, 9 Jan 2013 13:48:13 +0000 (UTC) From: Alexander Holler To: linux-kernel@vger.kernel.org Cc: linux-fbdev@vger.kernel.org, Bernie Thompson , Florian Tobias Schandinat , Alan Cox , Steve Glendinning , Dave Airlie , Alexander Holler , Subject: [PATCH v2] fb: udlfb: fix scheduling while atomic. Date: Wed, 9 Jan 2013 14:47:53 +0100 Message-Id: <1357739273-25913-1-git-send-email-holler@ahsoftware.de> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <50E9722D.2090602@ahsoftware.de> References: <50E9722D.2090602@ahsoftware.de> Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The console functions are using spinlocks while calling fb-driver ops but udlfb waits for a semaphore in many ops. This results in the BUG "scheduling while atomic". One of those call flows is e.g. vt_console_print() (spinlock printing_lock) (...) dlfb_ops_imageblit() dlfb_handle_damage() dlfb_get_urb() down_timeout(semaphore) BUG: scheduling while atomic (...) vt_console_print() (release spinlock printing_lock) Fix this through a workqueue for dlfb_handle_damage(). Cc: Signed-off-by: Alexander Holler --- drivers/video/udlfb.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++- include/video/udlfb.h | 1 + 2 files changed, 50 insertions(+), 1 deletion(-) diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c index 86d449e..4a90784 100644 --- a/drivers/video/udlfb.c +++ b/drivers/video/udlfb.c @@ -569,7 +569,7 @@ static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr, return 0; } -int dlfb_handle_damage(struct dlfb_data *dev, int x, int y, +int dlfb_handle_damage_queued(struct dlfb_data *dev, int x, int y, int width, int height, char *data) { int i, ret; @@ -630,6 +630,44 @@ error: return 0; } +struct dlfb_handle_damage_work { + struct work_struct my_work; + struct dlfb_data *dev; + char *data; + int x, y, width, height; +}; + +static void dlfb_handle_damage_work(struct work_struct *work) +{ + struct dlfb_handle_damage_work *my_work = + (struct dlfb_handle_damage_work *)work; + + dlfb_handle_damage_queued(my_work->dev, my_work->x, my_work->y, + my_work->width, my_work->height, my_work->data); + kfree(work); + return; +} + +void dlfb_handle_damage(struct dlfb_data *dev, int x, int y, + int width, int height, char *data) +{ + struct dlfb_handle_damage_work *work = + kmalloc(sizeof(struct dlfb_handle_damage_work), GFP_KERNEL); + + if (!work) { + pr_err("unable to allocate work\n"); + return; + } + INIT_WORK((struct work_struct *)work, dlfb_handle_damage_work); + work->dev = dev; + work->x = x; + work->y = y; + work->width = width; + work->height = height; + work->data = data; + queue_work(dev->handle_damage_wq, (struct work_struct *)work); +} + /* * Path triggered by usermode clients who write to filesystem * e.g. cat filename > /dev/fb1 @@ -945,6 +983,9 @@ static void dlfb_free_framebuffer(struct dlfb_data *dev) unregister_framebuffer(info); + if (dev->handle_damage_wq) + destroy_workqueue(dev->handle_damage_wq); + if (info->cmap.len != 0) fb_dealloc_cmap(&info->cmap); if (info->monspecs.modedb) @@ -1694,6 +1735,13 @@ static void dlfb_init_framebuffer_work(struct work_struct *work) goto error; } + dev->handle_damage_wq = alloc_workqueue("udlfb_damage", + WQ_MEM_RECLAIM, 0); + if (dev->handle_damage_wq == NULL) { + pr_err("unable to allocate workqueue\n"); + goto error; + } + /* ready to begin using device */ atomic_set(&dev->usb_active, 1); diff --git a/include/video/udlfb.h b/include/video/udlfb.h index f9466fa..1e765f9 100644 --- a/include/video/udlfb.h +++ b/include/video/udlfb.h @@ -43,6 +43,7 @@ struct dlfb_data { bool virtualized; /* true when physical usb device not present */ struct delayed_work init_framebuffer_work; struct delayed_work free_framebuffer_work; + struct workqueue_struct *handle_damage_wq; atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */ atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */ char *edid; /* null until we read edid from hw or get from sysfs */