On Fri, Jun 28, 2024 at 01:45:13PM +0000, Witold Sadowski wrote: > Hi Mark > > > + while (len) { > > > + tmp_buf = readq(addr); > > > + memcpy(buf, &tmp_buf, len > 8 ? 8 : len); > > > + len = len > 8 ? len - 8 : 0; > > > + buf += 8; > > > + } > > > +} > > Wouldn't it be more efficient and readable to only do the memcpy() for the > > trailing bytes and just do this memcpy() for the final word? > The whole problem is with SDMA end - addr in that case. If code will try to > Read it in non 64b mode, all remaining bits, will be lost. > For example - doing 1B read on that register, will return 1B, but SDMA will > transfer 8B, dropping remaining 7B. > I have tried memcpy approach, and it was not stable. That's not what I'm suggesting, like I said above I'm suggesting to *only* do the memcpy() for the trailing word.
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