On Thu, Nov 16, 2017 at 12:12 PM, ayaka <ayaka@xxxxxxxxxxx> wrote:
> #if 1
> for (i = 0; i < count; i++) {
> u32 *cur = (u32 *)buffer;
> u32 pos = offset + i * 4;
>
> cur += i;
> mpp_debug(DEBUG_SET_REG, "write reg[%03d]: %08x\n",
> pos, *cur);
> iowrite32(*cur, mpp_dev->reg_base + pos);
> }
> #else
> iowrite32_rep(mpp_dev->reg_base + offset, buffer, count);
> mb();
> for (i = 0; i < count; i++) {
> u32 cur = 0;
> u32 pos = offset / 4 + i;
>
> cur = ioread32(mpp_dev->reg_base + pos * 4);
> pr_info("get reg[%03d]: %08x\n", pos, cur);
> }
> #endif
The loop with iowrite32 writes consecutive u32 words from buffer
to consecutive IO memory locations. But iowrite32_rep writes
consecutive u32 words from buffer to the same IO memory location.
So they do different things when count > 1.
--
Thanks.
-- Max
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