From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85EE8282F20 for ; Tue, 21 Apr 2026 19:37:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776800249; cv=none; b=SMuG2izQ0vxbsqTUQbt+TtFWu8Echa/uOUW1aXLcyDBV8IaXtTJOnQBw13ZiDvQx4/t5tzKU70FnVcgja22Kwjw8r5CoXrjRNrHhfWPfHz+sC18joRbXYqTBFa6PYYzWVZRxTW0igTVs6Vf1IlK6dPTdj+EwLc3Orn8nav8W8q0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776800249; c=relaxed/simple; bh=LmHJCQE81gDA4eIuh7342wnbcDdwHRa2fESSfLS2vJc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jp8HUHl9lzjVwh/a15IaEF4OzfofpIqT9sN/UJR1g3qXUZ3kZKRSwfIFjue8pPCfM+6OZFkRJQXt9jWeWownLlNQU71kcb/hNHCJ+U25Wb0p5OreLURt+4dt5bbbP83huGWb3gh+VbF7twK6g8A6PpzK8yEJqIHvJ//hAD7eX70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=y6V6EKxL; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="y6V6EKxL" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4g0XgQ3H9vzlfl8L; Tue, 21 Apr 2026 19:37:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1776800238; x=1779392239; bh=q000bMpbrPKvirNnJbsCgREC 5Keqafr4ICnwKpWxnd8=; b=y6V6EKxLCZz+JoCrvNPdKgP4Nl5vyF9/qCDw2574 +nVJJchTSDfzC8jLepSXZ0eBbJagXcpoNsw0OaIdxYyA0Z+yit2bvcF+b6Z+2na4 AAVHXVvtxGSOrofyTA+r4jgCq6RNpXuhl40jbD9KpeB743wwJZt5RzkVuVPwCsFr 57nuWLfgLwuN2USI4g8mKPeJfZMb4gF3LNst9NH6ChtHusL3IMP7fWgnTB5O0Y+D +1cNfQ2NCyYoMiAW1tOqWomSeGlGiLG/i7OhGTTLvfTsd07ryaYsq6pi0t8UOvmy ESrqb9uHvE/fXe5EvQbdjDl/6VynhMUpZYRYqmQUMwPokQ== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id YAF4c7Bw4IdZ; Tue, 21 Apr 2026 19:37:18 +0000 (UTC) Received: from [100.119.48.131] (unknown [104.135.180.219]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4g0XgK0YmtzlfpM6; Tue, 21 Apr 2026 19:37:16 +0000 (UTC) Message-ID: <31c4e534-80e1-455d-8057-8b71a7616de5@acm.org> Date: Tue, 21 Apr 2026 12:37:16 -0700 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] ufs: core: Optimize ufshcd_add_uic_command_trace() To: =?UTF-8?B?UGV0ZXIgV2FuZyAo546L5L+h5Y+LKQ==?= , "martin.petersen@oracle.com" Cc: "linux-scsi@vger.kernel.org" , "beanhuo@micron.com" , "can.guo@oss.qualcomm.com" , "avri.altman@sandisk.com" , "James.Bottomley@HansenPartnership.com" , "adrian.hunter@intel.com" References: <20260417213027.3506742-1-bvanassche@acm.org> <20260417213027.3506742-4-bvanassche@acm.org> Content-Language: en-US From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 4/21/26 1:45 AM, Peter Wang (=E7=8E=8B=E4=BF=A1=E5=8F=8B) wrote: > In the complete case, all these commands and arguments 1 to 3 > are filled by hardware. If we do not read them from the hardware, > how can we be sure of the actual values written by the hardware? Hi Peter, Are we perhaps each interpreting the UFSHCI standard in a different way? My understanding is that the UFSHCI command flow is as follows: * First, UICCMDARG1, UICCMDARG2 and UICCMDARG3 are written by the host. * Next, UICCMD is written by the host. This causes the host controller to execute the UIC command. * Upon completion of the command, the host controller updates the lowest byte of UICCMDARG2. UICCMDARG3 is only updated after execution of the following commands has finished: DME_GET, DME_SET, DME_PEER_GET and DME_PEER_SET. Thanks, Bart.