Messages in this thread | | | Date | Sat, 24 Nov 2007 14:16:43 +0900 | From | Tejun Heo <> | Subject | Re: [PATCH] sata_nv: don't use legacy DMA in ADMA mode (v2) |
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Robert Hancock wrote: > We need to run any DMA command with result taskfile requested in ADMA mode > when the port is in ADMA mode, otherwise it may try to use the legacy DMA engine > in ADMA mode which is not allowed. Enforce this with BUG_ON() since data > corruption could potentially result if this happened. Also WARN_ON() if we try > and send result taskfile commands while NCQ commands are still active, since the > hardware doesn't allow this. > > Signed-off-by: Robert Hancock <hancockr@shaw.ca> > > @@ -1425,9 +1427,17 @@ > + /* We can't handle result taskfile with NCQ commands active, since > + retrieving the taskfile switches us out of ADMA mode and would abort > + existing commands. */ > + WARN_ON((qc->flags & ATA_QCFLAG_RESULT_TF) && > + (qc->ap->qc_allocated & ~(1 << qc->tag)));
I owe an apology here. ap->qc_allocated & ~(1 << qc->tag) test isn't correct. Sorry. qc deferring happens after qc is allocated so the condition can trigger (although it should be rare) even when nothing is going wrong, so I guess it should be WARN_ON((qc->flags & ATA_QCFLAG_RESULT_TF) && link->sactive).
Sorry. :-)
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