RE: [PATCH 2/5] media: synopsys: Add support for multiple streams

[G.N. Zhou (OSS)]

Hi Frank,

Thanks for your review.

> -----Original Message-----
> From: Frank Li <frank.li@xxxxxxx>
> Sent: Friday, April 17, 2026 4:38 PM
> To: G.N. Zhou (OSS) <guoniu.zhou@xxxxxxxxxxx>
> Cc: Michael Riesch <michael.riesch@xxxxxxxxxxxxx>; Mauro Carvalho Chehab
> <mchehab@xxxxxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski
> <krzk+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Heiko Stuebner
> <heiko@xxxxxxxxx>; Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>;
> linux-media@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-rockchip@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 2/5] media: synopsys: Add support for multiple streams
> 
> On Wed, Apr 15, 2026 at 11:46:53AM +0800, Guoniu Zhou wrote:
> > The current driver only supports single stream operation. Add support
> > for multiple concurrent streams by tracking enabled streams with a
> > bitmask and only initializing the hardware once for the first stream.
> >
> > This enables use cases such as surround view systems where multiple
> > camera streams need to be processed simultaneously through the same
> > CSI-2 receiver interface.
> 
> Look like this driver only one sink and one source pad, how to implement
> multiple stream.

Yes, you're correct that this driver has one sink pad and one source pad. The
multiple stream support is implemented using the V4L2 stream API, which
allows multiple logical streams to be multiplexed on a single pad.

In MIPI CSI-2, this corresponds to Virtual Channels (VC) and/or Data Types,
where multiple data streams can be transmitted over the same physical CSI-2
link. Each stream is identified by pad_index/stream_index (e.g., 0/0, 0/1, etc.).

> 
> Frank
> >
> > Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxxxxxx>
> > ---
> > 2.34.1
> >