From patchwork Mon Dec 7 16:42:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jae Hyun Yoo X-Patchwork-Id: 1412129 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CqTT01k0Nz9sWY for ; Tue, 8 Dec 2020 03:35:48 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CqTSy1KSdzDqVT for ; Tue, 8 Dec 2020 03:35:46 +1100 (AEDT) X-Original-To: openbmc@lists.ozlabs.org Delivered-To: openbmc@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.intel.com (client-ip=134.134.136.126; helo=mga18.intel.com; envelope-from=jae.hyun.yoo@linux.intel.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4CqTPq3XDfzDqNd; Tue, 8 Dec 2020 03:33:03 +1100 (AEDT) IronPort-SDR: irTWM7Adaz7c6VfqU7hx6bN2nes3G4Y0eycZXxkFwgR8IZAof6z4g2LSGpB6ndVf5LLt42f4uw o1LOUIU6jHDA== X-IronPort-AV: E=McAfee;i="6000,8403,9827"; a="161495853" X-IronPort-AV: E=Sophos;i="5.78,400,1599548400"; d="scan'208";a="161495853" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2020 08:33:00 -0800 IronPort-SDR: WlQxwyB0V1M4V9527ULq+RvgRgQS09YAl43Vzzkj6FL61An2RmNcjDfqJCsjw3KJnXK0qrs5MW vWCLkKGF53Hw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,400,1599548400"; d="scan'208";a="317246242" Received: from maru.jf.intel.com ([10.54.51.77]) by fmsmga008.fm.intel.com with ESMTP; 07 Dec 2020 08:33:00 -0800 From: Jae Hyun Yoo To: Joel Stanley , Andrew Jeffery , Eddie James , Stephen Boyd , Michael Turquette , Mauro Carvalho Chehab , Hans Verkuil Subject: [PATCH 2/2] media: aspeed: fix clock handling logic Date: Mon, 7 Dec 2020 08:42:40 -0800 Message-Id: <20201207164240.15436-3-jae.hyun.yoo@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201207164240.15436-1-jae.hyun.yoo@linux.intel.com> References: <20201207164240.15436-1-jae.hyun.yoo@linux.intel.com> X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: openbmc@lists.ozlabs.org, Jae Hyun Yoo , linux-clk@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-media@vger.kernel.org Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" Video engine uses eclk and vclk for its clock sources and its reset control is coupled with eclk so the current clock enabling sequence works like below. Enable eclk De-assert Video Engine reset 10ms delay Enable vclk It introduces improper reset on the Video Engine hardware and eventually the hardware generates unexpected DMA memory transfers that can corrupt memory region in random and sporadic patterns. This issue is observed very rarely on some specific AST2500 SoCs but it causes a critical kernel panic with making a various shape of signature so it's extremely hard to debug. Moreover, the issue is observed even when the video engine is not actively used because udevd turns on the video engine hardware for a short time to make a query in every boot. To fix this issue, this commit changes the clock handling logic to make the reset de-assertion triggered after enabling both eclk and vclk. Also, it adds clk_unprepare call for a case when probe fails. Fixes: d2b4387f3bdf ("media: platform: Add Aspeed Video Engine driver") Signed-off-by: Jae Hyun Yoo Reviewed-by: Joel Stanley Reviewed-by: Eddie James --- drivers/media/platform/aspeed-video.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c index c46a79eace98..db072ff2df70 100644 --- a/drivers/media/platform/aspeed-video.c +++ b/drivers/media/platform/aspeed-video.c @@ -514,8 +514,8 @@ static void aspeed_video_off(struct aspeed_video *video) aspeed_video_write(video, VE_INTERRUPT_STATUS, 0xffffffff); /* Turn off the relevant clocks */ - clk_disable(video->vclk); clk_disable(video->eclk); + clk_disable(video->vclk); clear_bit(VIDEO_CLOCKS_ON, &video->flags); } @@ -526,8 +526,8 @@ static void aspeed_video_on(struct aspeed_video *video) return; /* Turn on the relevant clocks */ - clk_enable(video->eclk); clk_enable(video->vclk); + clk_enable(video->eclk); set_bit(VIDEO_CLOCKS_ON, &video->flags); } @@ -1719,8 +1719,11 @@ static int aspeed_video_probe(struct platform_device *pdev) return rc; rc = aspeed_video_setup_video(video); - if (rc) + if (rc) { + clk_unprepare(video->vclk); + clk_unprepare(video->eclk); return rc; + } return 0; }