Sergei Shtylyov wrote:
Mark Lord wrote:
O> >> BTW, why the timeout is so damn long? 2*WAIT_CMD is 20 secs,
and if DMA is not complete or interrupt pending, it may wait 10 more secs...
..
I've lost the original question from this thread, but the idea of the
The original question concerned specifically the DMA command timeout
which is twice more than the usual one, WAIT_CMD (10 seconds).
longish
timeouts was that drive *may* be spun down ("standby"), and thus have
to spin
up again to complete media commands. Back then, drives were much
slower at
spinning up than nowadays, and the ATA spec says to allow up to 30
seconds.
Well, that doesn't explain the DMA case.
When a drive is in standby, we don't send it anything special to wake up.
So even DMA commands have to have a long enough timeout to allow
for spinning up.
Cheers
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