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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 93215C38A2C for ; Tue, 14 Apr 2020 15:10:47 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 218162085B for ; Tue, 14 Apr 2020 15:10:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="ZhLcFY7C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 218162085B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 7ABE716E3; Tue, 14 Apr 2020 17:09:55 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 7ABE716E3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1586877045; bh=oFMy1k18mvmf4OUSUBrAoalbWKdnhowqEDmrwSF7/J8=; h=Subject:To:References:From:Date:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=ZhLcFY7CBwCcAssxk7OIbyQnDmLgh8PJFg6SECmU4E3/9NnblXT7hrr0ON4s4zLvw BEoirWILRyjErHfbkALpakB3/+ct7QkmX8eIPBFZhgBhcTsx9houRBdUWanNJKX44b uTRuvBFOLaTmVegXlL/3cSBKi8g/6+Z9oF5xjdpc= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id DE2DCF8029A; Tue, 14 Apr 2020 16:50:34 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 17483F802A0; Tue, 14 Apr 2020 16:50:33 +0200 (CEST) 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 alsa1.perex.cz (Postfix) with ESMTPS id 75637F800F5 for ; Tue, 14 Apr 2020 16:50:28 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 75637F800F5 IronPort-SDR: HAui0ScrFw/ipP2kYCbVwFlJ1+skFfpzJov1NPlJsFpM756YJV3i16mhci1WJZBwX4GcOkQUOf 9noXTq/YQOzQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2020 07:50:26 -0700 IronPort-SDR: oa2zvcLMiMYunwJX3n9IURpRxFu+jBxtLqXxgNWnLVssizVt+6mI3tJD51M0AcDg3FlHIzddx0 hJZpPg6b0YGw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,382,1580803200"; d="scan'208";a="288238064" Received: from bjkulkar-mobl.amr.corp.intel.com (HELO [10.212.152.71]) ([10.212.152.71]) by fmsmga002.fm.intel.com with ESMTP; 14 Apr 2020 07:50:24 -0700 Subject: Re: [PATCH] ASoC: Intel: sst: ipc command timeout To: Brent Lu , alsa-devel@alsa-project.org References: <1586506705-3194-1-git-send-email-brent.lu@intel.com> From: Pierre-Louis Bossart Message-ID: <4f495cf1-4740-cf3b-196f-cc850c503b43@linux.intel.com> Date: Tue, 14 Apr 2020 09:50:24 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <1586506705-3194-1-git-send-email-brent.lu@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Cc: Kate Stewart , Cezary Rojewski , Richard Fontana , Greg Kroah-Hartman , Jie Yang , Takashi Iwai , linux-kernel@vger.kernel.org, Liam Girdwood , clang-built-linux@googlegroups.com, Mark Brown , Thomas Gleixner , Allison Randal X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On 4/10/20 3:18 AM, Brent Lu wrote: > After sending an ipc command to DSP, the host waits for the reply message > which will be read from SST_IPCD register in sst_byt_irq_thread() to > complete the transaction. Sometimes the value read from SST_IPCD register > is still the reply message for previous command instead of the waiting > command so ipc command timeout happens. > > In an experiment we read the same SST_IPCD register again when the defect > happens and found the value of second read is different from previous one > and is the correct reply message. It suggests the DSP is okay but the way > we read the register may be the cause. > > Currently the driver is using memcpy_fromio() to read the value of 64-bit > registers. This function is based on __builtin_memcpy() call and depends > on the implementation of compiler. Since this issue happens right after > the toolchain switched from clang 10 to clang 11, we replace the register > read with two readl() function calls to avoid all optimization from > compiler's library. I have mixed feelings about this. One one hand, this looks simple enough. But on the other hand we have other users of memcpy_fromio(), including SOF drivers, so what are the odds we have the same problems in other places? Wouldn't it be safer to either change this function so that it's behavior is not ambiguous or compiler-dependent, or fix the compiler? > > Signed-off-by: Brent Lu > --- > sound/soc/intel/common/sst-dsp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/sound/soc/intel/common/sst-dsp.c b/sound/soc/intel/common/sst-dsp.c > index ec66be2..12af7aa 100644 > --- a/sound/soc/intel/common/sst-dsp.c > +++ b/sound/soc/intel/common/sst-dsp.c > @@ -42,7 +42,7 @@ u64 sst_shim32_read64(void __iomem *addr, u32 offset) > { > u64 val; > > - memcpy_fromio(&val, addr + offset, sizeof(val)); > + sst_memcpy_fromio_32(NULL, &val, addr + offset, sizeof(val)); > return val; > } > EXPORT_SYMBOL_GPL(sst_shim32_read64); >