CHN_F_TRIGGERED
if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
c->flags |= CHN_F_TRIGGERED;
if (!(c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED))) {
c->flags &= ~CHN_F_TRIGGERED;
c->flags &= ~CHN_F_TRIGGERED;
#define CHN_STARTED(c) ((c)->flags & CHN_F_TRIGGERED)
if (wrch->flags & CHN_F_TRIGGERED)
if (rdch->flags & CHN_F_TRIGGERED)