> The FTAPBBRG020 supports the DMA functions for the AHB-to-AHB,
> AHB-to-APB, APB-to-AHB, and APB-to-APB transactions.
All the timer code in this file looks suspect. As a general rule everything
should be event driven and complete immediately (or at least schedule a BH for
immediate action if recursion is a concern), not relying on a periodic timer
interrupts.
> + qemu_mod_timer(s->qtimer,
> + qemu_get_clock_ns(vm_clock) + 1);
For all practical purposes this is going to happen immediately, so you should
not be using a timer.
> + qemu_mod_timer(s->qtimer,
> + qemu_get_clock_ns(vm_clock) + (get_ticks_per_sec() >> 2));
Why 0.25 seconds? Usually this sort of try-again-soon behavior means you've
missed a trigger event somewhere else.
> + if (!cpu_physical_memory_is_io(c->src)) {
> + src_map = src_ptr = cpu_physical_memory_map(c->src, &src_len, 0);
> + }
> + if (!cpu_physical_memory_is_io(c->dst)) {
> + dst_map = dst_ptr = cpu_physical_memory_map(c->dst, &dst_len, 1);
> + }
cpu_physical_memory_map might not map the whole region you requested. This
will cause badness in the subsequent code.
I suspect a log of this code anc and should be shared with your other DMA
controller, and probably several of the existing DMA controllers.
Paul
