Disables a direct memory access (DMA) channel.
#include <sys/types.h> #include <sys/errno.h> #include <sys/dma.h>
void d_mask (channel_id) int channel_id;
|channel_id||Specifies the DMA channel. This parameter is returned by the d_init service.|
The d_mask kernel service disables the DMA channel specified by the channel_id parameter.
The d_mask kernel service is typically called by a device driver deallocating the resources associated with its device. Some devices require it to be used during normal device operation to control DMA requests and avoid spurious DMA operations.
Note: The d_mask service, like all DMA services, should not be called unless the d_init service has allocated the DMA channel.
The d_mask kernel service can be called from either the process or interrupt environment.
The d_mask service has no return values.
The d_mask kernel service is part of Base Operating System (BOS) Runtime.
The d_init kernel service, d_unmask 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.