From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD7BDC282DD for ; Thu, 23 May 2019 19:22:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94B52206BA for ; Thu, 23 May 2019 19:22:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558639356; bh=eGjSZCeMlhs3mCdvp+rkNdXCGOMD6kWJsci1m1TlAcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pehVGnFina2Il/o9GzLRrAcbphLGZaqAL/27cn5GerGAuPrmolvaSzQ5Gyb4KihNy qpyWDpoSQWPsDqn9v9fU1eSfsew2Isd8lkhoAF1Qm3Szg61OmveP/K5uh/jFQ+j9ME 9kcs8ORcqV0+xx+7Dya4O0wlznUCCCsi/l18rZgQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389973AbfEWTWg (ORCPT ); Thu, 23 May 2019 15:22:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:60566 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389013AbfEWTWd (ORCPT ); Thu, 23 May 2019 15:22:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D8321206A3; Thu, 23 May 2019 19:22:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558639352; bh=eGjSZCeMlhs3mCdvp+rkNdXCGOMD6kWJsci1m1TlAcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sY5p4c/bHyX94j5EzerFeIx9jBNJhT3+y5XpPT50EplvsrPJF3YUt7Q7ZRrOfq8h0 z9S2b4RoNRU4Nr9bFJTMGHOUM4LJX0XzTMKdnayJU5dB/InLVDMbd0NTq9/abHVbp2 PKibm3Xch6qMHSzGzCnrn7E0Hp53dxDGYR+hkjdI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Bernie Thompson , Ladislav Michl , Bartlomiej Zolnierkiewicz Subject: [PATCH 5.0 056/139] udlfb: fix sleeping inside spinlock Date: Thu, 23 May 2019 21:05:44 +0200 Message-Id: <20190523181727.969949936@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190523181720.120897565@linuxfoundation.org> References: <20190523181720.120897565@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mikulas Patocka commit 6b11f9d8433b471fdd3ebed232b43a4b723be6ff upstream. If a framebuffer device is used as a console, the rendering calls (copyarea, fillrect, imageblit) may be done with the console spinlock held. On udlfb, these function call dlfb_handle_damage that takes a blocking semaphore before acquiring an URB. In order to fix the bug, this patch changes the calls copyarea, fillrect and imageblit to offload USB work to a workqueue. A side effect of this patch is 3x improvement in console scrolling speed because the device doesn't have to be updated after each copyarea call. Signed-off-by: Mikulas Patocka Cc: Bernie Thompson Cc: Ladislav Michl Cc: Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/udlfb.c | 56 +++++++++++++++++++++++++++++++++++++++++--- include/video/udlfb.h | 6 ++++ 2 files changed, 59 insertions(+), 3 deletions(-) --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -657,6 +657,50 @@ error: return 0; } +static void dlfb_init_damage(struct dlfb_data *dlfb) +{ + dlfb->damage_x = INT_MAX; + dlfb->damage_x2 = 0; + dlfb->damage_y = INT_MAX; + dlfb->damage_y2 = 0; +} + +static void dlfb_damage_work(struct work_struct *w) +{ + struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work); + int x, x2, y, y2; + + spin_lock_irq(&dlfb->damage_lock); + x = dlfb->damage_x; + x2 = dlfb->damage_x2; + y = dlfb->damage_y; + y2 = dlfb->damage_y2; + dlfb_init_damage(dlfb); + spin_unlock_irq(&dlfb->damage_lock); + + if (x < x2 && y < y2) + dlfb_handle_damage(dlfb, x, y, x2 - x, y2 - y); +} + +static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) +{ + unsigned long flags; + int x2 = x + width; + int y2 = y + height; + + if (x >= x2 || y >= y2) + return; + + spin_lock_irqsave(&dlfb->damage_lock, flags); + dlfb->damage_x = min(x, dlfb->damage_x); + dlfb->damage_x2 = max(x2, dlfb->damage_x2); + dlfb->damage_y = min(y, dlfb->damage_y); + dlfb->damage_y2 = max(y2, dlfb->damage_y2); + spin_unlock_irqrestore(&dlfb->damage_lock, flags); + + schedule_work(&dlfb->damage_work); +} + /* * Path triggered by usermode clients who write to filesystem * e.g. cat filename > /dev/fb1 @@ -693,7 +737,7 @@ static void dlfb_ops_copyarea(struct fb_ sys_copyarea(info, area); - dlfb_handle_damage(dlfb, area->dx, area->dy, + dlfb_offload_damage(dlfb, area->dx, area->dy, area->width, area->height); } @@ -704,7 +748,7 @@ static void dlfb_ops_imageblit(struct fb sys_imageblit(info, image); - dlfb_handle_damage(dlfb, image->dx, image->dy, + dlfb_offload_damage(dlfb, image->dx, image->dy, image->width, image->height); } @@ -715,7 +759,7 @@ static void dlfb_ops_fillrect(struct fb_ sys_fillrect(info, rect); - dlfb_handle_damage(dlfb, rect->dx, rect->dy, rect->width, + dlfb_offload_damage(dlfb, rect->dx, rect->dy, rect->width, rect->height); } @@ -940,6 +984,8 @@ static void dlfb_ops_destroy(struct fb_i { struct dlfb_data *dlfb = info->par; + cancel_work_sync(&dlfb->damage_work); + if (info->cmap.len != 0) fb_dealloc_cmap(&info->cmap); if (info->monspecs.modedb) @@ -1636,6 +1682,10 @@ static int dlfb_usb_probe(struct usb_int dlfb->ops = dlfb_ops; info->fbops = &dlfb->ops; + dlfb_init_damage(dlfb); + spin_lock_init(&dlfb->damage_lock); + INIT_WORK(&dlfb->damage_work, dlfb_damage_work); + INIT_LIST_HEAD(&info->modelist); if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) { --- a/include/video/udlfb.h +++ b/include/video/udlfb.h @@ -48,6 +48,12 @@ struct dlfb_data { int base8; u32 pseudo_palette[256]; int blank_mode; /*one of FB_BLANK_ */ + int damage_x; + int damage_y; + int damage_x2; + int damage_y2; + spinlock_t damage_lock; + struct work_struct damage_work; struct fb_ops ops; /* blit-only rendering path metrics, exposed through sysfs */ atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */