dma: dma channel null condition check

dma channel null condition check for pipelines
without using any of the specified dma channels.

Signed-off-by: maruthi machani <maruthi.machani@amd.corp-partner.google.com>

src/schedule/dma_multi_chan_domain.c

@@ -131,8 +131,10 @@ static int dma_multi_chan_domain_register(struct ll_schedule_domain *domain,
  if (!pipe_task->registrable)
  goto out;
 
- for (i = 0; i < dma_domain->num_dma; ++i) {
- for (j = 0; j < dmas[i].plat_data.channels; ++j) {
+ for (i = 0; i < dma_domain->num_dma ; ++i) {
+ if (dmas[i].chan == NULL)
+ continue;
+ for (j = 0; j < dmas[i].plat_data.channels ; ++j) {
  /* channel not set as scheduling source */
  if (!dma_is_scheduling_source(&dmas[i].chan[j]))
  continue;
@@ -222,7 +224,9 @@ static int dma_multi_chan_domain_unregister(struct ll_schedule_domain *domain,
  return 0;
 
  for (i = 0; i < dma_domain->num_dma; ++i) {
- for (j = 0; j < dmas[i].plat_data.channels; ++j) {
+ if (dmas[i].chan == NULL)
+ continue;
+ for (j = 0; j < dmas[i].plat_data.channels ; ++j) {
  /* channel not set as scheduling source */
  if (!dma_is_scheduling_source(&dmas[i].chan[j]))
  continue;
@@ -280,6 +284,8 @@ static bool dma_multi_chan_domain_is_pending(struct ll_schedule_domain *domain,
  int j;
 
  for (i = 0; i < dma_domain->num_dma; ++i) {
+ if (dmas[i].chan == NULL)
+ continue;
  for (j = 0; j < dmas[i].plat_data.channels; ++j) {
  if (!*comp) {
  status = dma_interrupt_legacy(&dmas[i].chan[j],