Android i.mx6 drm_hwcomposer

[Martin Fuzzey]

Hi,

I'm trying to get Android graphics working on i.MX6  using upstream 
versions:

Kernel 4.14

Mesa: mesa-17.3.0-rc2

Libdrm: libdrm-2.4.88

drm_hwcomposer (git head)

gbm_gralloc (git head from git://github.com/robherring)


I want to run on Android 5, which only has HWC1, the code for that is 
still in drm_hwcomposer but is not built anymore.
So I added that back and fixed up a few minor build errors.

The first problem I ran into was
     E/GRALLOC-GBM(  437): failed to create BO, size=1024x600, fmt=2, 
usage=5
     W/GraphicBufferAllocator(  437): alloc(1024, 600, 2, 00001a00, ...) 
failed -13 (Permission denied)

This was due to an GBM attempting to issue DRM_IOCTL_MODE_CREATE_DUMB on 
a render node.

Setting gralloc.gbm.device /dev/dri/card1  (the imx-drm node) instead of 
the default /dev/dri/renderD128 fixed that but then HWC couldn't become 
master on the DRI node to issue KMS commands since gralloc had already 
opened the device.

Adding a patch similar to:

commit 4f4cb902517f5caacea075fb9724e4ce0c435e3d
Author: Robert Foss <robert.foss at collabora.com>
Date:   Wed May 17 18:08:14 2017 -0400

     drm_hwcomposer: Get KMS FD from gbm_gralloc

To make drm_hwc and gbm_gralloc use the same FD fixed that.


But the problem I now have that when HWC tries to import the first 
client buffers (from bootanimation) there are errors like:

01-01 17:27:02.282   443   443 E hwc-platform-drm-generic: failed to 
import prime fd 25 ret=-1

This is because the imx-drm kernel driver wants physically contiguous 
buffers for import (it uses drm_gem_cma_prime_import_sg_table()) but the 
buffer allocated by drm etnaviv isn't contiguous...

Not sure what to do about that one.

Any help appreciated.

Martin