i use a AML-S905X-CC board and since the last kernel update, something start moving on the hardware acceleration side, i got mpv hwdec working. I would like to make some tests and start using kodi for media reproduction, but i'm scared that 256M of default cma memory is not enough.
I have tried to set the cma memory size from kernel parameters using armbian-config.
I have tried to add "cma=350M" and "extraargs=cma=350M" to boot environment.
Both commands does not work.
The strange thing is that i'm sure "extraargs=cma=350M" pass the command to the kernel parameters because i have already used it to disable a faulty composition output.
I have checked the syntax of the cma kernel parameter at the linux kernel documentation and SHOULD be ok, but i'm not sure 100%:
Spoiler
cma=nn[MG]@[start[MG][-end[MG]]] [ARM,X86,KNL] Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of memory allocations. A value of 0 disables CMA altogether. For more information, see include/linux/dma-contiguous.h
I verify the cma allocation from dmesg, that report:
[ 0.000000] Reserved memory: created CMA memory pool at 0x000000006b000000, size 256 MiB
I also verify it by using "cat /proc/meminfo" and on the end there is:
CmaTotal: 262144 kB
CmaFree: 12772 kB
So the question is: how can i change the cma allocation size, without recompile the kernel if possible?
Is it possible that the cma size has been hardwritten at compile time and runtime changes are ignored?
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UniformBuffer
Hi,
i use a AML-S905X-CC board and since the last kernel update, something start moving on the hardware acceleration side, i got mpv hwdec working. I would like to make some tests and start using kodi for media reproduction, but i'm scared that 256M of default cma memory is not enough.
I have tried to set the cma memory size from kernel parameters using armbian-config.
I have tried to add "cma=350M" and "extraargs=cma=350M" to boot environment.
Both commands does not work.
The strange thing is that i'm sure "extraargs=cma=350M" pass the command to the kernel parameters because i have already used it to disable a faulty composition output.
I have checked the syntax of the cma kernel parameter at the linux kernel documentation and SHOULD be ok, but i'm not sure 100%:
cma=nn[MG]@[start[MG][-end[MG]]] [ARM,X86,KNL] Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of memory allocations. A value of 0 disables CMA altogether. For more information, see include/linux/dma-contiguous.h
I verify the cma allocation from dmesg, that report:
[ 0.000000] Reserved memory: created CMA memory pool at 0x000000006b000000, size 256 MiB
I also verify it by using "cat /proc/meminfo" and on the end there is:
CmaTotal: 262144 kB
CmaFree: 12772 kB
So the question is: how can i change the cma allocation size, without recompile the kernel if possible?
Is it possible that the cma size has been hardwritten at compile time and runtime changes are ignored?
Thanks for the attention,
have a good day
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