Jeff Garzik wrote:
Tejun Heo wrote:
I didn't add DMA engine stopping to ata_bmdma_freeze() in this series.
When BMDMA engine is turned off, all status bits go too. However, the
status is used by BMDMA EH to report and to recognize host bus error
reprsented as timeout.
To make all of them work, the BMDMA status needs to be stored in
ata_bmdma_freeze() and used in EH, which is currently a bit difficult
to implement for generic BMDMA. I think we can resolve this later.
Agree re storing BMDMA status. The very next operation needs to be
DMA-stop, though. Otherwise shadow register block isn't accessible. And
you must still check BMDMA status -after- stopping DMA, too (that
doesn't invalidate your logic quoted above, of course).
I see. I think this can be done by making all BMDMA related stuff into
a layer between highlevel libata and BMDMA LLDDs. We can move all IO
ops into that layer and newer controllers like ahci, sata_sil24 and
sata_mv don't have to care about them. Have yet to think about how to
do it in simple way though, such that changes to BMDMA LLDDs are minimal.
Pulled into #upstream and other branches, and pushed to kernel.org.
Please check and make sure everything looks OK, after kernel.org
finishes mirroring to the outside world.
I glanced over them and diffed with my own tree. All look good & dandy.
BTW, it would be nice if you would start with branch #sii-irq when you
are updating the sata_sil interrupt handling path.
I certainly can, but I'm not sure it's a good idea to do it. Most
likely, it will end up in another rewriting of the rewritten irq handler
(commit-wise, it will be merge-sii-irq then rewrite sii-irq). The new
one in hp-LLDD-prep uses BMDMA2 to cut down on IO access and also makes
use of the fact that sata_sil uses ATA_DMA_INTR bit to indicate IRQ
pending even when non-DMA command is in progress, so the whole structure
is somewhat different from the one in sii-irq.
> And eventually we want to push #sii-lbt too.
Yeap, I looked at that one, too. But, IIRC, the test result wasn't too
positive. Am I remembering correctly?
--
tejun
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