Re: [RFC PATCH v0] Add tw5864 driver

From	Andrey Utkin <andrey.utkin@corp.bluecherry.net>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH v0] Add tw5864 driver
Date	2016-02-08 11:30 +0100
Message-ID	<qZReW-3Ut-1@gated-at.bofh.it> (permalink)
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On Mon, Feb 8, 2016 at 11:58 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> Hi Andrey,
>
> Hmm, it looks like I forgot to reply. Sorry about that.

Thank you very much anyway.

> I wouldn't change the memcpy: in my experience it is very useful to get a
> well-formed compressed stream out of the hardware. And the overhead of
> having to do a memcpy is a small price to pay and on modern CPUs should
> be barely noticeable for SDTV inputs.

So there's no usecase for scatter-gather approach, right?

> I don't believe that the lockups you see are related to the memcpy as
> such. The trace says that a cpu is stuck for 22s, no way that is related
> to something like that. It looks more like a deadlock somewhere.

There was a locking issue (lack of _irqsave) and was fixed since then.

> Regarding the compliance tests: don't pass VB2_USERPTR (doesn't work well
> with videobuf2-dma-contig). Also add vidioc_expbuf = vb2_ioctl_expbuf for
> the DMABUF support. That should clear up some of the errors you see.

Thank you!

-- 
Bluecherry developer.

Thread

Re: [RFC PATCH v0] Add tw5864 driver Hans Verkuil <hverkuil@xs4all.nl> - 2016-02-08 11:00 +0100
  Re: [RFC PATCH v0] Add tw5864 driver Andrey Utkin <andrey.utkin@corp.bluecherry.net> - 2016-02-08 11:30 +0100
    Re: [RFC PATCH v0] Add tw5864 driver Hans Verkuil <hverkuil@xs4all.nl> - 2016-02-08 11:30 +0100

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