Re: [PATCH V2] scsi: mpt3sas: remove redundant wmb

From: Brian King
Date: Fri Apr 21 2017 - 15:02:54 EST


On 04/21/2017 02:56 AM, Sreekanth Reddy wrote:
> On Thu, Apr 20, 2017 at 7:58 AM, Martin K. Petersen
> <martin.petersen@xxxxxxxxxx> wrote:
>> Sinan Kaya <okaya@xxxxxxxxxxxxxx> 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 <brking@xxxxxxxxxxxxxxxxxx>

-Brian

--
Brian King
Power Linux I/O
IBM Linux Technology Center