Re: [PATCH 4/4] media: platform: Add Aspeed Video Engine driver

[Eddie James]

On 08/29/2018 07:52 PM, Ezequiel Garcia wrote:
> Hi Eddie,
>
> On 29 August 2018 at 18:09, Eddie James <eajames@xxxxxxxxxxxxxxxxxx> wrote:
> > The Video Engine (VE) embedded in the Aspeed AST2400 and AST2500 SOCs
> > can capture and compress video data from digital or analog sources. With
> > the Aspeed chip acting a service processor, the Video Engine can capture
> > the host processor graphics output.
> >
> > Add a V4L2 driver to capture video data and compress it to JPEG images,
> > making the data available through a standard read interface.
> >
> > Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/media/platform/Kconfig        |    8 +
> >   drivers/media/platform/Makefile       |    1 +
> >   drivers/media/platform/aspeed-video.c | 1307 +++++++++++++++++++++++++++++++++
> >   3 files changed, 1316 insertions(+)
> >   create mode 100644 drivers/media/platform/aspeed-video.c
> >
> > diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> > index 94c1fe0..e599245 100644
> > --- a/drivers/media/platform/Kconfig
> > +++ b/drivers/media/platform/Kconfig
> > @@ -32,6 +32,14 @@ source "drivers/media/platform/davinci/Kconfig"
> >
> >   source "drivers/media/platform/omap/Kconfig"
> >
> > +config VIDEO_ASPEED
> > +       tristate "Aspeed AST2400 and AST2500 Video Engine driver"
> > +       depends on VIDEO_V4L2
> It seems you are not using videobuf2. I think it should simplify the read
> I/O part and at the same time expose the other capture methods.

Hi,

Well I'm not sure it would simplify the read interface; it's quite 
simple as it is, both in the driver and to set up in user-space.

I did get streaming I/O working but found the performance significantly 
worse than simple read calls, and therefore not worth the additional 
complexity.

Is it required that I support streaming?

Thanks,
Eddie

> There are plenty of examples to follow.
>
> Regards,
> Eze