Module Parameters — datadev

The datadev kernel module accepts parameters at load time via insmod or persistently via /etc/modprobe.d/.

Load-time example:

$ sudo insmod data_dev.ko cfgTxCount=2048 cfgRxCount=2048 cfgSize=262144

Persistent configuration (survives reboots when using modprobe):

# /etc/modprobe.d/datadev.conf
options datadev cfgTxCount=2048 cfgRxCount=2048 cfgSize=262144

Note

All parameters have permission 0 — they are not readable from /sys/module/datadev/parameters/ after the module is loaded. Use /proc/datadev_N to inspect the running configuration.

Parameter	Default	Description
cfgTxCount	1024	Number of TX DMA buffers allocated at module load. Increase for high-throughput write workloads at the cost of memory.
cfgRxCount	1024	Number of RX DMA buffers allocated at module load. Increase for high-throughput read workloads at the cost of memory.
cfgSize	0x20000 (131072 = 128 kB)	Size in bytes of each DMA buffer. Must be a power of two. Larger values reduce ioctl overhead for large transfers; smaller values reduce memory waste for small transfers.
cfgMode	1 (BUFF_COHERENT)	DMA buffer allocation mode. Valid values: 1 = BUFF_COHERENT (dma_alloc_coherent, CPU-coherent, default); 2 = BUFF_STREAM (kmalloc + dma_map_single, streaming); 4 = BUFF_ARM_ACP (ARM ACP path, RCE variants only).
cfgCont	1	RX continue enable. 1 = driver automatically returns received buffers to the free pool after the application reads them; 0 = application must call dmaRetIndex() explicitly.
cfgIrqHold	10000	Interrupt coalescing holdoff in hardware clock cycles. Higher values reduce interrupt rate at the cost of latency. Set to 0 to disable coalescing.
cfgIrqDis	0	Interrupt disable flag. 1 = disable hardware interrupts and use polling mode. Use with caution: polling consumes a CPU core.
cfgBgThold0	0	Buffer group threshold for channel group 0. 0 = no threshold enforced.
cfgBgThold1	0	Buffer group threshold for channel group 1.
cfgBgThold2	0	Buffer group threshold for channel group 2.
cfgBgThold3	0	Buffer group threshold for channel group 3.
cfgBgThold4	0	Buffer group threshold for channel group 4.
cfgBgThold5	0	Buffer group threshold for channel group 5.
cfgBgThold6	0	Buffer group threshold for channel group 6.
cfgBgThold7	0	Buffer group threshold for channel group 7.
cfgDevName	0	Device naming scheme. 0 = sequential (datadev_0, datadev_1, …); any nonzero value = PCI bus-number-based naming (datadev_1a, datadev_1b, …). Use nonzero when probe order is non-deterministic and stable names are required.
cfgTimeout	0xFFFF (65535)	Internal DMA transfer timeout duration in hardware clock cycles. Transfers that exceed this duration are aborted and flagged as errors.
cfgDebug	0	Enables very verbose kernel log output. 1 = verbose (use only for debugging — generates large log volume under load).