From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 008.lax.mailroute.net (008.lax.mailroute.net [199.89.1.11]) (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 CBB571F7092; Mon, 21 Oct 2024 18:35:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729535751; cv=none; b=eTcQt6TAUYObZrvfixnuBvDKYVoTJmQeY3rQ9GKLg7DJ8bO8NLIV94hjlx68cjxoK3B8XYfv+AT3PxnJtWi15OeXRGpG1vzL8BZGrbVkrovYYJPL1s8ffUl/mw4oka56zx64z7uyNSxMuF9G9HfVRsKSrwPGoVA0bM8bwSh5Nd0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729535751; c=relaxed/simple; bh=fcoHIyU9BrTO1ywot1l5OJbuuqqdunCfWz/jYowpd4Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Kj4HBld+ufRvsND2AE/OAVb8LmPnIkpTnXtnPHqMt8iQSRjY+Vw6P1vcVZCh/INVmvMlWd99zRrAqEbmdp6KqDVb8jnegLSMV42ykoocs+gTtP7nk0VAA4ectpGnn5sXmcrD+yZfU3OhTOhxvEvGLYgAYAfjOw/SHXLRHl86t4g= 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=LG02yGNt; arc=none smtp.client-ip=199.89.1.11 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="LG02yGNt" Received: from localhost (localhost [127.0.0.1]) by 008.lax.mailroute.net (Postfix) with ESMTP id 4XXPBs1dgjz6ClY9V; Mon, 21 Oct 2024 18:35:49 +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=1729535748; x=1732127749; bh=s7TCnzUvTpenS3OvUHYIdx3d 5tzL0dzFXbiwthYD1lI=; b=LG02yGNtfZ0JIfMMx/R+5dfXe9B4v+NRisWI0/YB 413sDcVtbOgM+ggufwmuz3QF2p70qfeI/nWiS3aJ/l9ST46F6tXz93objocAwtn6 6dmgjqIGcxetZlOJnJJSDCz1E2OTGrgvHwmF26ARdOQJptZbXgEv6cmBN4uK2D4s lPhuGRgJTUhf2TyT6eW7UON7qbRE3YgnfCqOIEueRZCvc3LftEerp/lQlvce92Hq 4naFH+CJczTa/Tt5q1ioP16WhRcxpArifVRXrCNUmk/ESX6vU7FOfPW5DUYLywQl iDoxMqM9ZwS+OZF77TAFvOHQhU9jPQSaaS1/uWIDDzRPrw== X-Virus-Scanned: by MailRoute Received: from 008.lax.mailroute.net ([127.0.0.1]) by localhost (008.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id Z-sTrmJdF5Tt; Mon, 21 Oct 2024 18:35:48 +0000 (UTC) Received: from [192.168.51.14] (c-73-231-117-72.hsd1.ca.comcast.net [73.231.117.72]) (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 008.lax.mailroute.net (Postfix) with ESMTPSA id 4XXPBp4Kw1z6ClY9R; Mon, 21 Oct 2024 18:35:46 +0000 (UTC) Message-ID: <85d2cb9b-75ba-4ab3-a50d-0f8161456fcb@acm.org> Date: Mon, 21 Oct 2024 11:35:42 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] scsi: ufs: core: Introduce a new host register lock To: Avri Altman , "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20241021120313.493371-1-avri.altman@wdc.com> <20241021120313.493371-2-avri.altman@wdc.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20241021120313.493371-2-avri.altman@wdc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/21/24 5:03 AM, Avri Altman wrote: > Introduce a new host register read/write lock. Use it to protect access > to the task management doorbell register: UTMRLDBR. This is not the > UTRLDBR which is already protected by its own outstanding_lock. Why is this necessary? I think it is allowed to submit host controller reads and writes simultaneously from different threads. Only read/modify/writes have to be serialized. Thanks, Bart.