Re: [linux-sunxi] [PATCH v12 0/2] Initial Allwinner V3s CSI Support

From: Yong
Date: Wed Dec 26 2018 - 05:38:35 EST


On Wed, 26 Dec 2018 11:29:36 +0100
'OndÅej Jirman' via linux-sunxi <linux-sunxi@xxxxxxxxxxxxxxxx> wrote:

> Hello,
> On Tue, Oct 30, 2018 at 04:09:48PM +0800, Yong Deng wrote:
> > I can't make v4l2-compliance always happy.
> > The V3s CSI support many pixformats. But they are not always available.
> > It's dependent on the input bus format (MEDIA_BUS_FMT_*).
> > Example:
> > But I can't get the subdev's format code before starting stream as the
> > subdev may change it. So I can't know which pixformats are available.
> > So I exports all the pixformats supported by SoC.
> > The result is the app (v4l2-compliance) is likely to fail on streamon.
> >
> > This patchset add initial support for Allwinner V3s CSI.
> I've tested your patches on A83T and CSI works on that SoC too. I'll send
> DTS patches later.
> One thing I noticed is that, when you cat the regmap registers file in debugfs
> while streaming, the kernel locks up hard. I was not able to extract any logs.

May be some registers can't be read when streaming ? Like read-clear regs ?
Or multi CPU core access regs at the same time may cause the bus lock up?