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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 AC5F7C433E0 for ; Mon, 10 Aug 2020 19:27:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8182422CA1 for ; Mon, 10 Aug 2020 19:27:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597087652; bh=jWqRiW4I0WKBGrfTOQRfUOvpMlfAxLk4XnkZZTMCiq8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NjqDlky7gXbYlEYpKVcSbLan25fE86JVFieBl5E451kr3a1cxo3BIn3JQzb77leHL r6aVUZvF+UuAVnDAugCKl40NfjV+7LGYnL+R1nUEwVLhzgVbQZ0DjUYdUAlU+Kn0BD H1LdJ3tkpkh0QGjtR1ytxv/5QMzkb8lvF0kA5/5w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728818AbgHJT10 (ORCPT ); Mon, 10 Aug 2020 15:27:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:39956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729319AbgHJTL3 (ORCPT ); Mon, 10 Aug 2020 15:11:29 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D1A4422B4B; Mon, 10 Aug 2020 19:11:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597086688; bh=jWqRiW4I0WKBGrfTOQRfUOvpMlfAxLk4XnkZZTMCiq8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eO8menNCQpuFZgPzo/ircOB0HGmMyOVhvhJJxD/Y5oxJ32lrXj7D601va8ZkUNNDt mqNnCwv6wOXdNqWAmFRGrUUJMmB9dah2QHu939KRrd1QmKAVlObhILNLwzmttWLxWV vpbxWbssgyeKsJ7FCUIKTqWLtLA7JCCCIGU1zd1w= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Osipenko , Thierry Reding , Sasha Levin , dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 43/60] gpu: host1x: debug: Fix multiple channels emitting messages simultaneously Date: Mon, 10 Aug 2020 15:10:11 -0400 Message-Id: <20200810191028.3793884-43-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200810191028.3793884-1-sashal@kernel.org> References: <20200810191028.3793884-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dmitry Osipenko [ Upstream commit 35681862808472a0a4b9a8817ae2789c0b5b3edc ] Once channel's job is hung, it dumps the channel's state into KMSG before tearing down the offending job. If multiple channels hang at once, then they dump messages simultaneously, making the debug info unreadable, and thus, useless. This patch adds mutex which allows only one channel to emit debug messages at a time. Signed-off-by: Dmitry Osipenko Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/gpu/host1x/debug.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/host1x/debug.c b/drivers/gpu/host1x/debug.c index c0392672a8421..1b4997bda1c79 100644 --- a/drivers/gpu/host1x/debug.c +++ b/drivers/gpu/host1x/debug.c @@ -16,6 +16,8 @@ #include "debug.h" #include "channel.h" +static DEFINE_MUTEX(debug_lock); + unsigned int host1x_debug_trace_cmdbuf; static pid_t host1x_debug_force_timeout_pid; @@ -52,12 +54,14 @@ static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo) struct output *o = data; mutex_lock(&ch->cdma.lock); + mutex_lock(&debug_lock); if (show_fifo) host1x_hw_show_channel_fifo(m, ch, o); host1x_hw_show_channel_cdma(m, ch, o); + mutex_unlock(&debug_lock); mutex_unlock(&ch->cdma.lock); return 0; -- 2.25.1