[PATCH 1/2 v4] drm/pl111: Support the Versatile Express

[Liviu Dudau]

On Mon, Apr 30, 2018 at 03:55:41PM +0100, Robin Murphy wrote:
> On 27/04/18 19:51, Linus Walleij wrote:
> > On Fri, Apr 27, 2018 at 5:02 PM, Robin Murphy <robin.murphy at arm.com> wrote:
> > 
> > > I dug a little bit and it seems pl111_modeset_init() is deferring because it
> > > can't find endpoint 0. And given that that's apparently pointing at some
> > > non-existent panel rather than the DVI encoder as I would (naively) expect,
> > > I can at least form a self-consistent explanation and give up on the grounds
> > > that I'm probably missing some important DT changes.
> > 
> > Yeah it does help if I also send the required DT changes :/
> > 
> > Sorry for my absentmindedness, I'll shoot it off right now so you
> > can test it.
> 
> Hooray, thanks for that.
> 
> For these 2 patches with a V2P-CA15_A7 tile and the DT fixed up,
> 
> Tested-by: Robin Murphy <robin.murphy at arm.com>
> 
> Framebuffer console and /dev/fb0 access for the motherboard CLCD works, and
> it keeps out of the way as expected with CONFIG_DRM_HDLCD=y. I can't
> convince an X session to start, but that appears more to do with sii902x
> falling apart*, which I can't be bothered to even try debugging.
> 
> Robin.
> 
> 
> *specifically, lots of this, which I imagine is related to xorg trying to
> either read the EDID or change mode:
> ...
> [  243.439669] i2c i2c-0: sendbytes: NAK bailout.
> [  243.454247] i2c i2c-0: sendbytes: NAK bailout.
> [  247.743261] i2c i2c-0: sendbytes: NAK bailout.
> [  247.770281] sii902x 0-0039: failed to read status (-6)
> [  247.786609] i2c i2c-0: sendbytes: NAK bailout.
> [  248.118522] i2c i2c-0: sendbytes: NAK bailout.
> [  248.145485] sii902x 0-0039: failed to read status (-6)
> [  248.177800] i2c i2c-0: sendbytes: NAK bailout.
> [  258.256500] i2c i2c-0: sendbytes: NAK bailout.
> [  258.274763] i2c i2c-0: sendbytes: NAK bailout.
> [  268.499637] i2c i2c-0: sendbytes: NAK bailout.
> [  268.517899] i2c i2c-0: sendbytes: NAK bailout.

That's a long standing issue that I've never got to the bottom of. The
sii902x seems to have been wired in a curious way on the VExpress board
and it is struggling to pass-through the I2C connection to the monitor.

Best regards,
Liviu

> ...
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-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
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