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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30EBBC433EF for ; Tue, 31 May 2022 02:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243491AbiEaCUe (ORCPT ); Mon, 30 May 2022 22:20:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233954AbiEaCUc (ORCPT ); Mon, 30 May 2022 22:20:32 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0D5D8CCE4; Mon, 30 May 2022 19:20:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1653963631; x=1685499631; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tsp2Js378HnMxOjZEQEeYwhoUZhRQiZFihQ/jcFVWAE=; b=gybibPWplaO42sU9a4avqrQyfqPlpufxVALjBR70cmlKWJ6Ip0I3C724 6UvwDL5vvMlaHkmpFPFZqnLSSLLMsY+2Vf2Apuzj8LEk8jeylUgto9gTA 4v3Lpz4AppJryWcXGkxcy2EglatY/YNQZI9HzR/jgt/EbXooTBK4ZPW73 JV4HuUCgE/YoWAo23oCbUKcXH4aJRBX70s+hUkvBkV8a4yI4k/Vj8jhVu ngpN4f5oYuDdd0aUQGcK2WGyFZoGV0vJBYcT7LIclCcipCXAI83hNqWxZ o66ltQlXBdrgJU0ExDxAmHYMq8qtLn6vMf0O4L8JnzOgs5n8errAzsBJB g==; X-IronPort-AV: E=McAfee;i="6400,9594,10363"; a="275202185" X-IronPort-AV: E=Sophos;i="5.91,263,1647327600"; d="scan'208";a="275202185" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 May 2022 19:20:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,263,1647327600"; d="scan'208";a="720103698" Received: from unknown (HELO localhost.localdomain) ([10.226.216.90]) by fmsmga001.fm.intel.com with ESMTP; 30 May 2022 19:20:29 -0700 From: tien.sung.ang@intel.com To: yilun.xu@intel.com Cc: dinh.nguyen@intel.com, hao.wu@intel.com, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, mdf@kernel.org, tien.sung.ang@intel.com, trix@redhat.com Subject: Re: [PATCH] fpga: altera-cvp: allow interrupt to continue next time Date: Tue, 31 May 2022 10:20:04 +0800 Message-Id: <20220531022004.2314963-1-tien.sung.ang@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220528120400.GA175058@yilunxu-OptiPlex-7050> References: <20220528120400.GA175058@yilunxu-OptiPlex-7050> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org >> CFG_READY signal/bit may time-out due to firmware not responding >> within the given time-out. This time varies due to numerous >> factors like size of bitstream and others. >> This time-out error does not impact the result of the CvP >> previous transactions. The CvP driver shall then, respond with >Do you mean the reprogramming is successful even if you find the time >out in write_complete()? Then return 0 is better? Based on the information given by the Intel FPGA firmware team, CFG_READY is essential to indicate if the current FPGA configuration session is indeed a success. There are cases we test in the lab whereby, CFG_READY stays invalid and the tests performed subsequently to verify the FPGA functionality could not detect the failed session. A failed FPGA configuration session means, the new bitstream wasn't successfully configured and tests ran later will just be passing on the previous working bitstream version. In short, CFG_READY is esential, and an error indicating the time-out is a must. Another example, using an incorrect SOF/Design FPGA results in CFG_READY being invalid. The user must be informed of a potential error. I will correct the wordings i used earlier that says that the timoeut error does not impact the results of the CvP previous transactions. It may so if the firmware has some sort of error. >And could you specify what the time-out mean on write_init() phase? I could not really understand your question. We set huge time-outs of ~10seconds. Every wait for the firmware to respond is potentially a hazard. The firmware CvP is has it's limitation unfortunately.