From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [PATCH V2] scsi: mpt3sas: remove redundant wmb Date: Fri, 21 Apr 2017 10:10:57 -0500 Message-ID: References: <1491591978-17880-1-git-send-email-okaya@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Sreekanth Reddy , "Martin K. Petersen" Cc: "James E.J. Bottomley" , Chaitra P B , "linux-scsi@vger.kernel.org" , linux-arm-msm@vger.kernel.org, timur@codeaurora.org, Sathya Prakash , open list , Sinan Kaya , Suganath Prabu Subramani , "open list:LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)" , linux-arm-kernel@lists.infradead.org List-Id: linux-arm-msm@vger.kernel.org On 04/21/2017 02:56 AM, Sreekanth Reddy wrote: > On Thu, Apr 20, 2017 at 7:58 AM, Martin K. Petersen > wrote: >> Sinan Kaya writes: >> >>> Due to relaxed ordering requirements on multiple architectures, >>> drivers are required to use wmb/rmb/mb combinations when they need to >>> guarantee observability between the memory and the HW. >>> >>> The mpt3sas driver is already using wmb() for this purpose. However, >>> it issues a writel following wmb(). writel() function on arm/arm64 >>> arhictectures have an embedded wmb() call inside. > > [Sreekanth] Whether same thing applicable for SPARC & POWER > architectures. If yes then we are fine with this patch changes. This is also true for Power. Reviewed-by: Brian King -Brian -- Brian King Power Linux I/O IBM Linux Technology Center