imxdrm issue on SABRE Lite

[Dan MacDonald]

Hi Phillipp

On Mon, Feb 20, 2017 at 3:42 PM, Philipp Zabel <p.zabel at pengutronix.de> wrote:
> Hi Dan,
>
> On Sat, 2017-02-11 at 21:09 +0000, Dan MacDonald wrote:
>> Hi Phillipp
>>
>> I'm having trouble getting xf86-video-armada working properly on a
>> Element 14 / Embest SABRE Lite board running Arch Linux with kernel
>> 4.9.8. I have been in touch with RMK and he's confident the crash
>> below is caused by a kernel issue relating to imxdrm and a null
>> pointer dereference.
>
> I can't reproduce this on v4.9.8 with a Nitrogen6X with 1280x800 LDVS
> panel and 1920x1080 HDMI monitor using modetest from libdrm. Does this
> only happen with X?

I have read that there are supposedly differences between the Element
14 SL and the Boundary Devices board of the same name but I have yet
to find out exactly what they are as the specs are the same on paper.
Saying that, all of the uboot and OS images for the BD SL that I've
tried have worked without issue, including the GLES demos on the BD
Ubuntu 16.04 image.

I've never used wayland. The console works fine with my 4K display and
I have been able to get X running at 720x480 under Arch with armada
but no other resolution.

> Do you have framebuffer console emulation enabled?

Not sure - will need to check if thats enable by default under ALARM?
I've not manually enabled it.

> Does this still happen if you disable the LVDS panel in the device tree?

Russell sent me a different dtb file which seemed to fix some of my
kernel probs. Russell will be able to explain that better than me.

>
>> The first indiction of X/armada not being happy it that it only starts
>> in 720x480 when connected to a 4K HDMI display, and when I try
>> running:
>>
>> xrandr --output HDMI1 --mode 1920x1080
>>
>> X crashes.
>>
>> Here's the serial console output for X loading and then crashing after
>> I try running that xrandr command:
>>
>>  Arch Linux 4.9.8-1-ARCH (ttymxc1)
>>
>> alarm login: [   19.197477] fec 2188000.ethernet eth0: Link is Up -
>> 1Gbps/Full - flow control rx/tx
>> [   19.205165] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
>> [   33.080000] vgaarb: this pci device is not a vga device
>> [   33.203520] vgaarb: this pci device is not a vga device
>> [   33.447051] imx-ipuv3 2400000.ipu: DC stop timeout after 50 ms
>
> Does the "gpu: ipu-v3: remove IRQ dance on DC channel disable" patch
> (https://patchwork.kernel.org/patch/9417683) do anything to improve the
> situation, besides removing the above warning?

After trying Russells dtb, he asked me to try booting with:

setenv bootargs cma=256M

Then X failed to start with the error:

[   57.705889] imx-drm display-subsystem: failed to allocate buffer
with size 33177600

Do you think that patch could fix such an issue?

Thanks