[Mesa-dev] [PATCH 4/4] egl/dri2: add image extension to swrast_core_extensions

[Emil Velikov]

Hi Gurchetan,

Pardon for the delay.

On 22 June 2017 at 00:40, Gurchetan Singh <gurchetansingh at chromium.org> wrote:
> Emil,
>
> If I understand you correctly, you're proposing to add the ability to use
> the kms_swrast driver in platform_x11.c (the host is a standard Ubuntu box
> for the emulator use case, not CrOS) alongside swrast.
>
> In that case, we would need to:
>
> 1) Have a dri2_initialize_x11_kms_swrast function that's called when some
> environment variable is set instead of dri2_initialize_x11_swrast.
There is the obvious caveat that LIBGL_ALWAYS_SOFTWARE should be set.

Other than that - we can try kms_swrast and fallback to swrast.
If the former is very incomplete relative to the latter then we might
consider adding another envvar.

> 2) dri2_initialize_x11_kms_swrast would need access to the host card fd
> (dri_kms_init_screen requires this) and call dri2_load_driver instead of
> dri2_load_driver_swrast .
Indeed - in the GBM case, we get that from the user. In here, we
_should_ be able to use the existing one passed from X. See below for
more.

> 3) Use dri2_loader_extensions instead of swrast_loader_extensions,
> dri2_x11_display_vtbl instead dri2_x11_swrast_display_vtbl etc.
>
Correct again.

> I'm having trouble getting this to work, and I was wondering if what I'm
> trying to do is what you want.  Attached is the patch I'm trying (it
> compiles, but will crash your display).
>
Please keep patches a) inline and b) functional changes separate from
code movement.
Fishing for ~5 diff in a 100 line patch isn't fun :-\

Re the issue:
 - opening card0 without authenticating is a serious no-go
 - at the same time we shouldn't need the open - reuse the fd, as
mentioned above.
 - if above does not work use the renderD for the given fd ->
open(drmGetRenderDeviceNameFromFd(fd)...)


> Regarding the issues with the emulator, I filed a bug based your comments
> and the emulator team has started looking at it (see
> https://android-review.googlesource.com/#/c/418541/).
>
Great, glad to hear that it is getting resolved.

Thanks
Emil