Problem importing buffer allocated by etnaviv to imx-drm

[Martin Fuzzey]

Hi Robert,

Latest update: it works!

Thank you for your help!


On 12/07/18 14:45, Robert Foss wrote:
> Hey Martin (& Chris),
>
> This has been a re-occuring pain point on devices with multiple DRM 
> nodes to chose from, but recently I added node probing support to mesa 
> which lets you avoid hardcoded paths.
>
> https://cgit.freedesktop.org/mesa/mesa/commit/?id=c7bb82136b48b99427465ba4fa3ce477cf09e097 
>
>

Yes indeed thank you, I just saw that. It should let me get rid of the 
hack below

>>
>> I also tried leaving the gbm_gralloc allocation parameter alone and 
>> modifying imx_drm_screen_create() to use /dev/dri/card1 for .kms_fd 
>> with the same result.
>>
>> --- a/src/gallium/winsys/imx/drm/imx_drm_winsys.c
>> +++ b/src/gallium/winsys/imx/drm/imx_drm_winsys.c
>>   struct pipe_screen *imx_drm_screen_create(int fd)
>>   {
>>      struct renderonly ro = {
>>         .create_for_resource = 
>> renderonly_create_kms_dumb_buffer_for_resource,
>> -      .kms_fd = fd,
>> +      //.kms_fd = fd,
>> +      .kms_fd = open("/dev/dri/card1", O_RDWR | O_CLOEXEC), // MF Hack
>>         .gpu_fd = open("/dev/dri/renderD128", O_RDWR | O_CLOEXEC)
>>      };
>>
>>
> Rob Herrings has mentioned that pushing a dev branch for the 
> gbm_gralloc handle support is on his Todo list.
> But for now there is another branch, which reportedly has been working 
> better.
>
> https://github.com/robherring/gbm_gralloc/commits/handle-rework-v2
>

Yes, just found that this morning too.

That is the key to getting it to work due to this patch which is on that 
branch:

commit 137cc39aaa57f8c64db3397cd6ec7600a191a88d
Author: Mauro Rossi <issor.oruam at gmail.com>
Date:   Fri Jun 29 13:45:10 2018 +0200

     Update usage flag handling for hwc

     Add support for GRALLOC_USAGE_HW_COMPOSER usage flag
     mapping it to GBM flags, inspired by minigbm implementation.

     Fixes the artifacts issues with vulkan hal radv with the following apps
     with benefit to all apps using HWC layers:
     V1 - GPU Benchmark Pro (Vulkan API)
     PPSSPP - PSP emulator
     Sascha Willems Vulkan Examples (e.g. Vulkan Gears, Vulkan Texture)

     Signed-off-by: Mauro Rossi <issor.oruam at gmail.com>
     Signed-off-by: Rob Herring <robh at kernel.org>

diff --git a/gralloc_gbm.cpp b/gralloc_gbm.cpp
index 247fba7..cd37f4d 100644
--- a/gralloc_gbm.cpp
+++ b/gralloc_gbm.cpp
@@ -147,6 +147,8 @@ static unsigned int get_pipe_bind(int usage)
                 bind |= GBM_BO_USE_RENDERING;
         if (usage & GRALLOC_USAGE_HW_FB)
                 bind |= GBM_BO_USE_SCANOUT;
+       if (usage & GRALLOC_USAGE_HW_COMPOSER)
+               bind |= GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING;

         return bind;
  }


Since android tags buffers that will be sent to HWC with 
GRALLOC_USAGE_HW_COMPOSER they will now be allocated from imx-drm rather 
than etnaviv which solves the import problem.

That branch also fixes the structure mismatch problem I mentionned but 
requires cherry picking this commit from mesa master so that egl will 
compile

commit 3f7bca44d9a9f07eaafc5de850ec65bdd00707b9
Author: Rob Herring <robh at kernel.org>
Date:   Thu Apr 26 16:02:01 2018 +0200

     egl/android: #ifdef out flink name support


So, I now have it all working, at least to the bootanimation (my boot 
doesn't go further for the moment, for reasons unrelated to the graphics 
stack).


The only nasty thing remaining is the DRM permissions hack in the kernel.

This is required because the renderonly code uses the imx-drm node to 
allocate scanout and hw composer buffers and also to do 
drmPrimeHandleToFD() from the graphics allocator process.

But the same device node is opened by the  HWC process and it is HWC 
that is DRM master.

So, without the kernel hack, drmPrimeHandleToFD() for the scanout / hw 
composer buffers fails.


Ways I can think of to fix this:

1) Use AUTHMAGIC ? (But I think that's more or less deprecated today) 
and it would require communicating the token between HWC and gralloc
2) Share the fd between gralloc and hwc? Seems to be creating unwanted 
coupling.
3) Modify the imx-drm kernel driver to provide a render node and use 
that in the renderonly code

#3 looks the best to me at the moment.

Regards,

Martin


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/etnaviv/attachments/20180712/c5f33dc7/attachment.html>