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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 E4AF6C433DF for ; Mon, 17 Aug 2020 19:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1C4220674 for ; Mon, 17 Aug 2020 19:41:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597693286; bh=jWqRiW4I0WKBGrfTOQRfUOvpMlfAxLk4XnkZZTMCiq8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dq1tKB2MwmwhoRsSPtd847t34Uyj+x3JkM/HpcgofiunAJ1oCoUR7uoM+DHmEWNuk 9G6FxG53iO8RGYQYf7JwRxft2w48NzqunR+VbBEx2qwYEEuP30YfsM2epiJDlgGUxe s8BJs1u5VIybwSP10QZiMK2QgeEMgzUJHQiNLs/I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404280AbgHQTlW (ORCPT ); Mon, 17 Aug 2020 15:41:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:58422 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729131AbgHQPZO (ORCPT ); Mon, 17 Aug 2020 11:25:14 -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 A5E472310F; Mon, 17 Aug 2020 15:25:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597677912; bh=jWqRiW4I0WKBGrfTOQRfUOvpMlfAxLk4XnkZZTMCiq8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=osKzxK9f9+2fVk5QsDNDUGB4DquqZzgFu9IVIlPdoV43hw3mW1ZhSXnQrQb7PBqsD teuUI3fenVILkOc+rrqYhPRhHSswOAmB8Uw1zCREVeGWNBNxynfbT1WOnnzjTwCJ8C uI+T29wf1hFv6VeamSokLqxTERl6VjuPqJR4n6YI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Osipenko , Thierry Reding , Sasha Levin Subject: [PATCH 5.8 123/464] gpu: host1x: debug: Fix multiple channels emitting messages simultaneously Date: Mon, 17 Aug 2020 17:11:16 +0200 Message-Id: <20200817143839.704870535@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@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: 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