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=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 6759DC433E1 for ; Mon, 17 Aug 2020 17:49:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BDA12067C for ; Mon, 17 Aug 2020 17:49:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597686573; bh=cUwC9Yi8xFwUR3ud0kfob6ueTPMUW+ozY7s6/mmjJgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1nq1Hn9rUpwqsbWkVgodayX/61Jr5BE1uflkfcEdF0fMxzvPKeOMuNaSc8vablqsb 39+gHac29Mll+0mAJdz+Ee3baQUyf7at1VXnS+mp2/gv7wVebDxaw0wRWEb+wHZaHu 5mkPLshHlBai2N88WxQKXkYWf5nRNbbuhF4C9cUo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390141AbgHQRtc (ORCPT ); Mon, 17 Aug 2020 13:49:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:45042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388711AbgHQQMm (ORCPT ); Mon, 17 Aug 2020 12:12:42 -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 2853920772; Mon, 17 Aug 2020 16:12:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597680761; bh=cUwC9Yi8xFwUR3ud0kfob6ueTPMUW+ozY7s6/mmjJgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E9CdS8Z89pfXZsEuoi2/h1IwIYhVjTP5Do1wB60d3FoBsF9qtJ6SI70lSua7pSZN1 CixI7NAmGlOx6FAmOBCtXZg1VZ70YkTBrIrlbP6lt0+l1/7p2jHHhfBc97fZc8RrWb AqhqGkf7HGn7gVSKsH3YoRbkOFUFULkhdSFmK7xM= 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 4.19 047/168] gpu: host1x: debug: Fix multiple channels emitting messages simultaneously Date: Mon, 17 Aug 2020 17:16:18 +0200 Message-Id: <20200817143736.104308167@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143733.692105228@linuxfoundation.org> References: <20200817143733.692105228@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 329e4a3d8ae7b..6c9ad4533999c 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; @@ -61,12 +63,14 @@ 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