From: Rob Herring <robh@kernel.org>
To: Daniele Alessandrelli <daniele.alessandrelli@linux.intel.com>
Cc: mgross@linux.intel.com, daniele.alessandrelli@intel.com,
markgross@kernel.org, arnd@arndb.de, bp@suse.de,
damien.lemoal@wdc.com, gregkh@linuxfoundation.org,
corbet@lwn.net, leonard.crestez@nxp.com,
palmerdabbelt@google.com, paul.walmsley@sifive.com,
peng.fan@nxp.com, shawnguo@kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
Jassi Brar <jassisinghbrar@gmail.com>
Subject: Re: [PATCH 02/22] dt-bindings: Add bindings for Keem Bay IPC driver
Date: Wed, 9 Dec 2020 11:33:35 -0600 [thread overview]
Message-ID: <20201209173335.GA644399@robh.at.kernel.org> (raw)
In-Reply-To: <ca099c0833dc79f0a88edecd9fb949157eacbf46.camel@linux.intel.com>
On Mon, Dec 07, 2020 at 06:42:07PM +0000, Daniele Alessandrelli wrote:
> Hi Rob,
>
> Thanks for the feedback.
>
> On Mon, 2020-12-07 at 10:01 -0600, Rob Herring wrote:
> > On Tue, Dec 01, 2020 at 02:34:51PM -0800, mgross@linux.intel.com wrote:
> > > From: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
> > >
> > > Add DT binding documentation for the Intel Keem Bay IPC driver, which
> > > enables communication between the Computing Sub-System (CSS) and the
> > > Multimedia Sub-System (MSS) of the Intel Movidius SoC code named Keem
> > > Bay.
> > >
>
> [cut]
>
> > > +
> > > +description:
> > > + The Keem Bay IPC driver enables Inter-Processor Communication (IPC) with the
> > > + Visual Processor Unit (VPU) embedded in the Intel Movidius SoC code named
> > > + Keem Bay.
> >
> > Sounds like a mailbox.
>
> We did consider using the mailbox framework, but eventually decided
> against it; mainly because of the following two reasons:
>
> 1. The channel concept in the Mailbox framework is different than the
> channel concept in Keem Bay IPC:
>
> a. My understanding is that Mailbox channels are meant to be SW
> representation of physical HW channels, while in Keem Bay IPC
> channels are software abstractions to achieve communication
> multiplexing over a single HW link
>
> b. Additionally, Keem Bay IPC has two different classes of channels
> (high-speed channels and general-purpose channels) that need to
> access the same HW link with different priorities.
>
> 2. The blocking / non-blocking TX behavior of mailbox channels is
> defined at channel creation time (by the tx_block value of the
> mailbox client passed to mbox_request_channel(); my understanding
> is that the tx_block value cannot be modified after the channel is
> created), while in Keem Bay IPC the same channel can be used for
> both blocking and non-blocking TX (behavior is controlled by the
> timeout argument passed to keembay_ipc_send()).
>
> Having said that, I guess that it could be possible to create a Mailbox
> driver implementing the core communication mechanism used by the Keem
> Bay IPC and then build our API around it (basically having two
> drivers). But I'm not sure that would make the code simpler or easier
> to maintain. Any thoughts on this?
The use of the mailbox binding and the kernel's mailbox framework are
independent questions. I'm only concerned with the former (for purposes
of this review).
Rob
next prev parent reply other threads:[~2020-12-09 17:34 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 22:34 [PATCH 00/22] Intel Vision Processing Unit base enabling part 1 mgross
2020-12-01 22:34 ` [PATCH 01/22] Add Vision Processing Unit (VPU) documentation mgross
2020-12-18 23:30 ` Randy Dunlap
2021-01-07 20:16 ` mark gross
2020-12-01 22:34 ` [PATCH 02/22] dt-bindings: Add bindings for Keem Bay IPC driver mgross
2020-12-07 16:01 ` Rob Herring
2020-12-07 18:22 ` mark gross
2020-12-07 18:42 ` Daniele Alessandrelli
2020-12-07 20:31 ` Jassi Brar
2020-12-09 0:12 ` mark gross
2020-12-09 16:49 ` Jassi Brar
2020-12-09 17:33 ` Rob Herring [this message]
2020-12-01 22:34 ` [PATCH 03/22] keembay-ipc: Add Keem Bay IPC module mgross
2020-12-02 6:16 ` Greg KH
2020-12-02 17:42 ` mark gross
2020-12-02 19:01 ` Greg KH
2020-12-05 3:35 ` mark gross
2020-12-05 8:40 ` Greg KH
2020-12-05 16:37 ` Gross, Mark
2020-12-07 1:36 ` mark gross
2020-12-02 6:19 ` Greg KH
2020-12-08 18:59 ` Daniele Alessandrelli
2020-12-08 19:48 ` Greg KH
2020-12-10 18:38 ` Daniele Alessandrelli
2020-12-11 8:22 ` Greg KH
2020-12-11 17:26 ` Gross, Mark
2020-12-01 22:34 ` [PATCH 04/22] dt-bindings: Add bindings for Keem Bay VPU IPC driver mgross
2020-12-07 15:57 ` Rob Herring
2020-12-07 21:28 ` mark gross
2020-12-01 22:34 ` [PATCH 05/22] keembay-vpu-ipc: Add Keem Bay VPU IPC module mgross
2020-12-01 22:34 ` [PATCH 06/22] misc: xlink-pcie: Add documentation for XLink PCIe driver mgross
2020-12-18 22:59 ` Randy Dunlap
2020-12-19 0:07 ` mark gross
2020-12-01 22:34 ` [PATCH 07/22] misc: xlink-pcie: lh: Add PCIe EPF driver for Local Host mgross
2020-12-01 22:34 ` [PATCH 08/22] misc: xlink-pcie: lh: Add PCIe EP DMA functionality mgross
2020-12-01 22:34 ` [PATCH 09/22] misc: xlink-pcie: lh: Add core communication logic mgross
2020-12-02 6:18 ` Greg KH
2020-12-02 16:46 ` Thokala, Srikanth
2020-12-01 22:34 ` [PATCH 10/22] misc: xlink-pcie: lh: Prepare changes for adding remote host driver mgross
2020-12-01 22:35 ` [PATCH 11/22] misc: xlink-pcie: rh: Add PCIe EP driver for Remote Host mgross
2020-12-01 22:35 ` [PATCH 12/22] misc: xlink-pcie: rh: Add core communication logic mgross
2020-12-01 22:35 ` [PATCH 13/22] misc: xlink-pcie: Add XLink API interface mgross
2020-12-01 22:35 ` [PATCH 14/22] misc: xlink-pcie: Add asynchronous event notification support for XLink mgross
2020-12-01 22:35 ` [PATCH 15/22] xlink-ipc: Add xlink ipc device tree bindings mgross
2020-12-07 15:58 ` Rob Herring
2020-12-07 21:41 ` mark gross
2020-12-01 22:35 ` [PATCH 16/22] xlink-ipc: Add xlink ipc driver mgross
2020-12-07 2:32 ` Joe Perches
2020-12-11 11:33 ` Kelly, Seamus
2020-12-11 12:14 ` gregkh
2020-12-11 17:12 ` Gross, Mark
2020-12-07 19:53 ` Randy Dunlap
2020-12-01 22:35 ` [PATCH 17/22] xlink-core: Add xlink core device tree bindings mgross
2020-12-07 16:02 ` Rob Herring
2020-12-01 22:35 ` [PATCH 18/22] xlink-core: Add xlink core driver xLink mgross
2020-12-07 21:50 ` Randy Dunlap
2020-12-01 22:35 ` [PATCH 19/22] xlink-core: Enable xlink protocol over pcie mgross
2020-12-01 22:35 ` [PATCH 20/22] xlink-core: Enable VPU IP management and runtime control mgross
2020-12-01 22:35 ` [PATCH 21/22] xlink-core: add async channel and events mgross
2020-12-07 2:55 ` Joe Perches
2020-12-11 11:34 ` Kelly, Seamus
2020-12-01 22:35 ` [PATCH 22/22] xlink-core: factorize xlink_ioctl function by creating sub-functions for each ioctl command mgross
2020-12-07 3:05 ` Joe Perches
2020-12-07 21:59 ` mark gross
2020-12-09 8:30 ` Joe Perches
2020-12-11 11:36 ` Kelly, Seamus
-- strict thread matches above, loose matches on Subject: below --
2020-11-30 23:06 [PATCH 00/22] Intel Vision Processing Unit base enabling part 1 mgross
2020-11-30 23:06 ` [PATCH 02/22] dt-bindings: Add bindings for Keem Bay IPC driver mgross
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