Re: [RFC PATCH] Add bridge driver to connect sensors to CIO2 device via software nodes on ACPI platforms

From: Kieran Bingham <kieran.bingham@ideasonboard.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Dan Scally <djrscally@gmail.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Yong Zhi <yong.zhi@intel.com>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Bingbu Cao <bingbu.cao@intel.com>,
	Tian Shu Qiu <tian.shu.qiu@intel.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Rob Herring <robh@kernel.org>,
	"open list:STAGING SUBSYSTEM" <devel@driverdev.osuosl.org>,
	jorhand@linux.microsoft.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	Tsuchiya Yuto <kitakar@gmail.com>
Subject: Re: [RFC PATCH] Add bridge driver to connect sensors to CIO2 device via software nodes on ACPI platforms
Date: Thu, 17 Sep 2020 15:19:36 +0100	[thread overview]
Message-ID: <f48ec4c5-0674-2e43-cbd8-f5dcc4bf5b15@ideasonboard.com> (raw)
In-Reply-To: <CAHp75VcjSZC7BG9ckFTogTK0xXog9tev8i3w=P0iN4JRQY05XQ@mail.gmail.com>

Hi Andy,

On 17/09/2020 15:08, Andy Shevchenko wrote:
> On Thu, Sep 17, 2020 at 4:31 PM Kieran Bingham
> <kieran.bingham@ideasonboard.com> wrote:
>> On 17/09/2020 10:47, Dan Scally wrote:
>>> On 17/09/2020 08:53, Greg KH wrote:
>>>> On Wed, Sep 16, 2020 at 10:36:18PM +0100, Daniel Scally wrote:
> 
>>>>>  drivers/staging/media/ipu3/Kconfig       |  15 +
>>>>>  drivers/staging/media/ipu3/Makefile      |   1 +
>>>>>  drivers/staging/media/ipu3/cio2-bridge.c | 448 +++++++++++++++++++++++
>>>> Why does this have to be in drivers/staging/ at all?  Why not spend the
>>>> time to fix it up properly and get it merged correctly?  It's a very
>>>> small driver, and should be smaller, so it should not be a lot of work
>>>> to do.  And it would be faster to do that than to take it through
>>>> staging...
>>> I was just under the impression that that was the process to be honest,
>>> if that's not right I'll just move it directly to drivers/media/ipu3
>>
>> The IPU3 driver is still in staging (unless I've missed something), so I
>> think this cio2-bridge should stay with it.
> 
> You missed something.
> https://elixir.bootlin.com/linux/v5.9-rc5/source/drivers/media/pci/intel
> 
> IPU3 from Freescale (IIRC) is a different story.

Ayee, ok so we have 'half' the driver for IPU3 out of staging.

From my understanding, the IPU3 consists of two components, the CIO2
(CSI2 capture), and the IMGU (the ISP).

- drivers/media/pci/intel/ipu3

This is indeed the CIO2 component (config VIDEO_IPU3_CIO2), and that is
the part that this bridge relates to, so in fact this cio2-bridge should
probably go there indeed. No need to go through staging.

The files remaining at:

- drivers/staging/media/ipu3

are in fact also for the IPU3 but the ISP component (VIDEO_IPU3_IMGU).

I'm sorry for the confusion, I knew that the ISP was still in staging, I
hadn't realised the CSI2 receiver (CIO2) was not.

>> Hopefully with more users of the IPU3 brought in by this cio2-bridge,
>> that will help gather momentum to get the IPU3 developments required
>> completed and moved into drivers/media.

-- 
Regards
--
Kieran