Re: [PATCH 0/2] drm/vc4: Fixes for Raspberry Pi 3

[Daniel Stone]

Hi,

On 1 March 2016 at 01:52, Eric Anholt <eric@xxxxxxxxxx> wrote:
> These are for fixing the vc4 driver on the Pi 3.  Note that patch 2
> will also be necessary for fixing HPD on the Pi2, which we've been
> carrying downstream patches to work around until now.

Indeed. Having cherry-picked 80032d2e61 and added ACTIVE_LOW to the
bcm2836-rpi-2-b DT, I now get HPD reported correctly.

I think it might still need work: on RPi2 again, DDC fails on boot
(the same BCM2835_I2C_S_ERR bit being set, i.e. 'i2c transfer failed:
100'), and does work after a hotplug cycle. But the machine then
immediately hard-hangs - no serial console - after cat
/sys/class/drm/card0-HDMI-A-1/edid.

On the grounds that the VC4 node isn't yet in upstream DT though, and
this _does_ indeed fix HPD:
Tested-by: Daniel Stone <daniels@xxxxxxxxxxxxx>

Cheers,
Daniel