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,USER_AGENT_GIT autolearn=ham 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 E4D7DC433E0 for ; Mon, 10 Aug 2020 19:17:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B87192080C for ; Mon, 10 Aug 2020 19:17:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597087065; bh=h4djccU8SRHv5HAmTc/Lbs8dPuas84jJHHnm4Ggawq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dzNjIGw3s2jp/cLQw8f6hD11Imgv8AFk5VD0d3Ezbvxu1QjPgk23w+misyrff5OIA 9sUC4VsvHNbYTcY5F08bQ6ciNN+PMKgTxGAfSdBPiIDsitrR8LbJ0r2BiJ91oD41cd x6IbUj6RKsuGWM8Jy6820Rm+0rEP8gNeesQJmEpM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728846AbgHJTOQ (ORCPT ); Mon, 10 Aug 2020 15:14:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:45958 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729264AbgHJTOH (ORCPT ); Mon, 10 Aug 2020 15:14:07 -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 1524B22BED; Mon, 10 Aug 2020 19:14:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597086847; bh=h4djccU8SRHv5HAmTc/Lbs8dPuas84jJHHnm4Ggawq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jF7TTUIKK9qajq2WX43m9/ty/UDvfxTJRvR8zRarVP5IZ/q9CxQrS3xXM19egwydb 1uYN0nczMDCwd0FUJB+RqctfdBzFxZLJhwJX0V6EKiTYOraJ+RM67GqUxCaM1QayRK 26Gys+hBdhfMa31iUiymI/zsXhckLlUY/hWrUd74= 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 4.14 15/22] gpu: host1x: debug: Fix multiple channels emitting messages simultaneously Date: Mon, 10 Aug 2020 15:13:37 -0400 Message-Id: <20200810191345.3795166-15-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200810191345.3795166-1-sashal@kernel.org> References: <20200810191345.3795166-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 2aae0e63214c2..0b8c23c399c2a 100644 --- a/drivers/gpu/host1x/debug.c +++ b/drivers/gpu/host1x/debug.c @@ -25,6 +25,8 @@ #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; @@ -49,12 +51,14 @@ 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