Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Nava kishore Manne <navam@xilinx.com>
To:     Moritz Fischer <mdf@kernel.org>
CC:     "trix@redhat.com" <trix@redhat.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        Michal Simek <michals@xilinx.com>,
        "linux-fpga@vger.kernel.org" <linux-fpga@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        git <git@xilinx.com>,
        "chinnikishore369@gmail.com" <chinnikishore369@gmail.com>
Subject: RE: [PATCH 2/2] fpga: Add support for Xilinx DFX AXI Shutdown manager
Thread-Topic: [PATCH 2/2] fpga: Add support for Xilinx DFX AXI Shutdown
 manager
Thread-Index: AQHW6t9xKUyYsQdkFk2NaePj2u7pYKopkSiAgATukeCABKWmAIAIFNLg
Date:   Wed, 27 Jan 2021 08:46:15 +0000
Message-ID: <MWHPR02MB26230510C77BF1FBBB571898C2BB9@MWHPR02MB2623.namprd02.prod.outlook.com>
References: <20210115013431.27667-1-nava.manne@xilinx.com>
 <20210115013431.27667-2-nava.manne@xilinx.com> <YAJWT4IDPmHneam1@epycbox.lan>
 <MWHPR02MB262353F2D236B6AD787FD5EFC2A30@MWHPR02MB2623.namprd02.prod.outlook.com>
 <YApfYL5swV46IsQG@archbook>
In-Reply-To: <YApfYL5swV46IsQG@archbook>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 36c2cbb2-b8e7-480b-fdb2-08d8c2a001c1
X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Jan 2021 08:46:15.2162
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 657af505-d5df-48d0-8300-c31994686c5c
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: vHvJRc7D3n3LyCNtCRWUUOFWmptPVIf8KS7m9lLJMNtdNcHapQP6NLK+QrWWikeZUNb+FkrbvV0/DdrDnTr1Kg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW2PR02MB3882
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Moritz,

	Please find my response inline.

> -----Original Message-----
> From: Moritz Fischer <mdf@kernel.org>
> Sent: Friday, January 22, 2021 10:45 AM
> To: Nava kishore Manne <navam@xilinx.com>
> Cc: Moritz Fischer <mdf@kernel.org>; trix@redhat.com;
> robh+dt@kernel.org; Michal Simek <michals@xilinx.com>; linux-
> fpga@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; git
> <git@xilinx.com>; chinnikishore369@gmail.com
> Subject: Re: [PATCH 2/2] fpga: Add support for Xilinx DFX AXI Shutdown
> manager
>=20
> On Tue, Jan 19, 2021 at 06:34:54AM +0000, Nava kishore Manne wrote:
> > Hi Moritz,
> >
> > 	Thanks for the review.
> > Please find my response inline.
> >
> > > -----Original Message-----
> > > From: Moritz Fischer <mdf@kernel.org>
> > > Sent: Saturday, January 16, 2021 8:28 AM
> > > To: Nava kishore Manne <navam@xilinx.com>
> > > Cc: mdf@kernel.org; trix@redhat.com; robh+dt@kernel.org; Michal
> > > Simek <michals@xilinx.com>; linux-fpga@vger.kernel.org;
> > > devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> > > linux- kernel@vger.kernel.org; git <git@xilinx.com>;
> > > chinnikishore369@gmail.com
> > > Subject: Re: [PATCH 2/2] fpga: Add support for Xilinx DFX AXI
> > > Shutdown manager
> > >
> > > Hi,
> > >
> > > On Fri, Jan 15, 2021 at 07:04:31AM +0530, Nava kishore Manne wrote:
> > > > This patch adds support for Xilinx Dynamic Function eXchange(DFX)
> > > > AXI shutdown manager IP. It can be used to safely handling the AXI
> > > > traffic on a Reconfigurable Partition when it is undergoing
> > > > dynamic reconfiguration and there by preventing system deadlock
> > > > that may occur if AXI transactions are interrupted during
> reconfiguration.
> > > >
> > > > PR-Decoupler and AXI shutdown manager are completely different IPs.
> > > > But both the IP registers are compatible and also both belong to
> > > > the same sub-system (fpga-bridge).So using same driver for both IP'=
s.
> > >
> > > I'm a bit confused, the whole goal here is to give the thing a differ=
ent
> name?
> >
> >
> > Both the PR Decoupler and AXI Shutdown IP manager IP's are follows same
> register spec.
> > Most of the code is common so we thought of reusing  same driver for AX=
I
> shutdown manager as well.
>=20
> What are the differences, though other than it shows a different name?

The PR-Decoupler And Axi Shut down manager are different IP's=20

PR-Decoupler IP can be used to make the interface between a Reconfigurable =
Partition
and the static logic safe while Partial Reconfiguration is occurring. When =
active,
user-selected signals crossing between the Reconfigurable Partition and the=
 static logic
are driven to user configurable values. When inactive, signals are passed u=
naltered.

Coming to the Axi Shutdown manager IP it's safely handles AXI4MM and AXI4-L=
ite interfaces
on a Reconfigurable Partition when it is undergoing dynamic reconfiguration=
 (DFX),
preventing system deadlock that can occur if AXI transactions are interrupt=
ed by DFX.

For more details please refer the below links:
https://www.xilinx.com/support/documentation/ip_documentation/pr_decoupler/=
v1_0/pg227-pr-decoupler.pdf=20
https://www.xilinx.com/support/documentation/ip_documentation/dfx_axi_shutd=
own_manager/v1_0/pg377-dfx-axi-shutdown-manager.pdf =20

Both the IP functionality's are different but the IP's registers spec is sa=
me and also they fall under
the same bridge drivers category and most of the code is common except the =
naming conventions.
So we thought of using the same driver for both the IP's with different nam=
ing conventions.

Regards,
Navakishore.