Re: [mpt3sas driver 07/10] mpt3sas: Add support for configurable Chain Frame Size
From: Tomas Henzl
Date: Mon Feb 08 2016 - 08:55:29 EST
On 5.2.2016 08:56, Sreekanth Reddy wrote:
> On Thu, Feb 4, 2016 at 8:35 PM, Tomas Henzl <thenzl@xxxxxxxxxx> wrote:
>> On 28.1.2016 07:37, Suganath prabu Subaramani wrote:
>>> From: Suganath prabu Subramani <suganath-prabu.subramani@xxxxxxxxxxxxx>
>>>
>>> Added support for configurable Chain Frame Size. Calculate the
>>> Chain Message Frame size from the IOCMaxChainSegementSize (iocfacts).
>>> Applicable only for mpt3sas/SAS3.0 HBA's.
>>>
>>> Signed-off-by: Suganath prabu Subramani <suganath-prabu.subramani@xxxxxxxxxxxxx>
>>> Signed-off-by: Chaitra P B <chaitra.basappa@xxxxxxxxxxxxx>
>> Is this done in order to prepare for some future patch, or how does it work?
>> I noticed only changes in allocation of (probably larger) fields, but
>> how is it actually used ?
> Tomas,
>
> In this patch set we have added new Intruder and Cutlass (high ports)
> PCI devices which are based on MPI26 version.
> In this MPI26 version, Request Frame size is doubled when compared to
> older MPI version, but their is
> no change in the Chain buffer size from MPI26 to older versions. In
> older version Request frame size and
> chain buffer size were same, so in the drivers previously we used to
> use Request Frame size reference for
> Chain buffer size. But we can't use that reference now. So now we are
> determining the chain buffer size from
> IOCFact's IOCMaxChainSegementSize field instead of using the Request
> frame size reference.
>
> ~Sreekanth
Thanks,
Reviewed-by: Tomas Henzl <thenzl@xxxxxxxxxx>
Tomas