GStreamer dmabufheaps problem

[MicMoba]

After switching to Kernel 6.6 I am not able to get GStreamer running.

I suppose that there is problem with the dma.

imx8mp:~$ GST_DEBUG=*dma*:5 gst-launch-1.0 videotestsrc ! autovideosink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
0:00:00.072033375   889 0xffff88000b70 WARN       dmabufheapsmemory gstdmabufheaps.c:98:gst_dmabufheaps_allocator_mem_init: Could not open dmabufheaps driver
0:00:00.072123500   889 0xffff88000b70 WARN       dmabufheapsmemory gstdmabufheaps.c:119:gst_dmabufheaps_allocator_obtain: No allocator named dmabufheapsmem found

(gst-launch-1.0:889): GStreamer-CRITICAL **: 06:27:14.679: gst_buffer_pool_config_set_allocator: assertion 'allocator != NULL || params != NULL' failed
0:00:00.077851750   889 0xffff88000b70 WARN       dmabufheapsmemory gstdmabufheaps.c:119:gst_dmabufheaps_allocator_obtain: No allocator named dmabufheapsmem found

(gst-launch-1.0:889): GStreamer-CRITICAL **: 06:27:14.684: gst_buffer_pool_config_set_allocator: assertion 'allocator != NULL || params != NULL' failed

(gst-launch-1.0:889): GStreamer-CRITICAL **: 06:27:14.685: gst_object_unref: assertion 'object != NULL' failed
0:00:00.078302375   889 0xffff88000b70 DEBUG              wl_dmabuf gstwllinuxdmabuf.c:141:gst_wl_linux_dmabuf_construct_wl_buffer:<GstWlDisplay@0xaaaaec76ec60> Creating wl_buffer from DMABuf of size 307200 (320 x 240), DRM fourcc AR24

(gst-launch-1.0:889): GStreamer-Allocators-CRITICAL **: 06:27:14.685: gst_dmabuf_memory_get_fd: assertion 'gst_is_dmabuf_memory (mem)' failed
error marshalling arguments for add: dup failed: Bad file descriptor
Error marshalling request: Bad file descriptor
0:00:01.078829000   889 0xffff88000b70 ERROR              wl_dmabuf gstwllinuxdmabuf.c:217:gst_wl_linux_dmabuf_construct_wl_buffer:<allocatorsysmem0> zwp_linux_buffer_params_v1 time out
0:00:01.078882000   889 0xffff88000b70 ERROR              wl_dmabuf gstwllinuxdmabuf.c:225:gst_wl_linux_dmabuf_construct_wl_buffer:<allocatorsysmem0> can't create linux-dmabuf buffer
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
Redistribute latency...
New clock: GstSystemClock
^Chandling interrupt.
Interrupt: Stopping pipeline ...
Execution ended after 0:00:02.173458875
Setting pipeline to NULL ...

 I use the wayland display server, weston (v 12.0.4) as compositor and gstreamer v1.24.0

Is there a missmatch of versions between VPU, GPU, DMA, ...? How can I check this? In the output abov is a warning "Could not open dmabufheaps driver". What driver is meant? Who provides this driver?

Actually I use the meta-imx layer for the graphics and multimedia stuff. Maybe it's a rights issue.
I miss myself a idea to investigate this problem. So I will be thankfull to get any suggestions.

[MicMoba]

I made some investigations and found out that there were two devices renamed.

/dev/dma_heap/linux,cma is called now /dev/dma_heap/reserved

/dev/dma_heap/linux,cma-uncached is called now /dev/dma_heap/reserved-uncached

I made two symbolic links to this new devices with the old names and now the gstreamer works well.

Why are the devices renamed? And how can I change this?

[MicMoba · Accepted solution]

I found the reason for the renaming. If the kernel config CONFIG_CMA_SIZE_MBYTES is below the

given size of linux,cma item in the devicetree the new kernel rename the device to "reserved".

In my case the kernel config was:

CONFIG_CMA_SIZE_MBYTES=320

The devicetree (imx8mp.dtsi):

resmem: reserved-memory {
   #address-cells = <2>;
   #size-cells = <2>;
   ranges;

   ocram: ocram@900000 {
      no-map;
      reg = <0 0x900000 0 0x70000>;
   };

/*
*    Memory reserved for optee usage. Please do not use.
*    This will be automaticky added to dtb if OP-TEE is installed.
*    optee@56000000 {
*       reg = <0 0x56000000 0 0x2000000>;
*       no-map;
*    };
*/
   /* global autoconfigured region for contiguous allocations */
   linux,cma {
      compatible = "shared-dma-pool";
      reusable;
      size = <0 0x3C000000>;
      alloc-ranges = <0 0x40000000 0 0xC0000000>;
      linux,cma-default;
   };
...

0x3C000000 is 960MiB. So it was over the 320MiB from the kernel configuration. After I changed the size to 0x14000000 the device names in /dev/dma_heap were as expect with linux,cma and linux,cma-uncached.

[Bio_TICFSL]

Hello,

ok you reduced the cma address and it works for you.

Regards

[Bio_TICFSL]

Hello,

which BSP are you using? which target board? since you don't need to change the dma or cma memories and its not changing between bsps.

Regards