Frees a direct memory access (DMA) channel.
#include <sys/types.h> #include <sys/errno.h> #include <sys/dma.h>
void d_clear (channel_id) int channel_id;
|channel_id||DMA channel identifier returned by the d_init service.|
The d_clear kernel service cleans up a DMA channel. To clean up the DMA channel:
The d_clear service is typically called by a device driver in its close routine. It has no return values.
Attention: The d_clear service, as with all DMA services, should not be called unless the DMA channel has been successfully allocated with the d_init service. The d_complete service must have been called to clean up after any DMA transfers. Otherwise, data will be lost and the system integrity will be compromised.
The d_clear kernel service can be called from either the process or interrupt environment.
The d_clear kernel service has no return values.
The d_clear kernel service is part of Base Operating System (BOS) Runtime.
The d_complete kernel service, d_init kernel service.
I/O Kernel Services and Understanding Direct Memory Access (DMA) Transfers in AIX Version 4.3 Kernel Extensions and Device Support Programming Concepts.