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 5AE48C282DD for ; Thu, 23 May 2019 19:16:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FE722186A for ; Thu, 23 May 2019 19:16:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558638968; bh=a9UcbVbIAa9yFWsS81lStfkrnBa1VMhlC8V7xi8PUFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oSjznP6TR0ZXJW2/x3hSjzAiEiD79WeqUPy40GI6PjG5myqszk0uepGE3V12hjJyo XkyIdXqSu140wmr7AnPTgm9q3ynMCyILOniuYmutPq4afIQyUYdWrHg+VSIiDJZmbW bngHrRbFAxfMUhvEtvIDTAbF/cANgfs/6OtpmY+k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389120AbfEWTQG (ORCPT ); Thu, 23 May 2019 15:16:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:50620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389107AbfEWTQD (ORCPT ); Thu, 23 May 2019 15:16:03 -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 EC13C2133D; Thu, 23 May 2019 19:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558638962; bh=a9UcbVbIAa9yFWsS81lStfkrnBa1VMhlC8V7xi8PUFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G3pJ8Ht+Rq1bfPpKPAa7CP/nb4hyw+zKeTb/JYOXYBJJlMjTg6J7WT/im9QCTIiFM TQsR7PIa95910goxvOymSCoTGVH8ibgGE+6HNc5m+r6u6I6Y6RUTDU29QmSfRwRFRD MoQlJf0rsuvFCE6Rs6Ye4RAFGuizMLyamtL9puHY= 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 4.19 045/114] udlfb: introduce a rendering mutex Date: Thu, 23 May 2019 21:05:44 +0200 Message-Id: <20190523181735.798552427@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190523181731.372074275@linuxfoundation.org> References: <20190523181731.372074275@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 babc250e278eac7b0e671bdaedf833759b43bb78 upstream. Rendering calls may be done simultaneously from the workqueue, dlfb_ops_write, dlfb_ops_ioctl, dlfb_ops_set_par and dlfb_dpy_deferred_io. The code is robust enough so that it won't crash on concurrent rendering. However, concurrent rendering may cause display corruption if the same pixel is simultaneously being rendered. In order to avoid this corruption, this patch adds a mutex around the rendering calls. Signed-off-by: Mikulas Patocka Cc: Bernie Thompson Cc: Ladislav Michl Cc: [b.zolnierkie: replace "dlfb:" with "uldfb:" in the patch summary] Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/udlfb.c | 41 ++++++++++++++++++++++++++++++----------- include/video/udlfb.h | 1 + 2 files changed, 31 insertions(+), 11 deletions(-) --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -596,7 +596,7 @@ static int dlfb_render_hline(struct dlfb static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) { - int i; + int i, ret; char *cmd; cycles_t start_cycles, end_cycles; int bytes_sent = 0; @@ -606,21 +606,29 @@ static int dlfb_handle_damage(struct dlf start_cycles = get_cycles(); + mutex_lock(&dlfb->render_mutex); + aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long)); width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long)); x = aligned_x; if ((width <= 0) || (x + width > dlfb->info->var.xres) || - (y + height > dlfb->info->var.yres)) - return -EINVAL; + (y + height > dlfb->info->var.yres)) { + ret = -EINVAL; + goto unlock_ret; + } - if (!atomic_read(&dlfb->usb_active)) - return 0; + if (!atomic_read(&dlfb->usb_active)) { + ret = 0; + goto unlock_ret; + } urb = dlfb_get_urb(dlfb); - if (!urb) - return 0; + if (!urb) { + ret = 0; + goto unlock_ret; + } cmd = urb->transfer_buffer; for (i = y; i < y + height ; i++) { @@ -654,7 +662,11 @@ error: >> 10)), /* Kcycles */ &dlfb->cpu_kcycles_used); - return 0; + ret = 0; + +unlock_ret: + mutex_unlock(&dlfb->render_mutex); + return ret; } static void dlfb_init_damage(struct dlfb_data *dlfb) @@ -782,17 +794,19 @@ static void dlfb_dpy_deferred_io(struct int bytes_identical = 0; int bytes_rendered = 0; + mutex_lock(&dlfb->render_mutex); + if (!fb_defio) - return; + goto unlock_ret; if (!atomic_read(&dlfb->usb_active)) - return; + goto unlock_ret; start_cycles = get_cycles(); urb = dlfb_get_urb(dlfb); if (!urb) - return; + goto unlock_ret; cmd = urb->transfer_buffer; @@ -825,6 +839,8 @@ error: atomic_add(((unsigned int) ((end_cycles - start_cycles) >> 10)), /* Kcycles */ &dlfb->cpu_kcycles_used); +unlock_ret: + mutex_unlock(&dlfb->render_mutex); } static int dlfb_get_edid(struct dlfb_data *dlfb, char *edid, int len) @@ -986,6 +1002,8 @@ static void dlfb_ops_destroy(struct fb_i cancel_work_sync(&dlfb->damage_work); + mutex_destroy(&dlfb->render_mutex); + if (info->cmap.len != 0) fb_dealloc_cmap(&info->cmap); if (info->monspecs.modedb) @@ -1682,6 +1700,7 @@ static int dlfb_usb_probe(struct usb_int dlfb->ops = dlfb_ops; info->fbops = &dlfb->ops; + mutex_init(&dlfb->render_mutex); dlfb_init_damage(dlfb); spin_lock_init(&dlfb->damage_lock); INIT_WORK(&dlfb->damage_work, dlfb_damage_work); --- a/include/video/udlfb.h +++ b/include/video/udlfb.h @@ -48,6 +48,7 @@ struct dlfb_data { int base8; u32 pseudo_palette[256]; int blank_mode; /*one of FB_BLANK_ */ + struct mutex render_mutex; int damage_x; int damage_y; int damage_x2;