Albert Lee wrote:
ata_check_atapi_dma() fix for LLDDs with the ATA_FLAG_PIO_POLLING flag.
Signed-off-by: Albert Lee <albertcc@xxxxxxxxxx>
---
We don't support polling DMA.
If the LLDD handles only interrupts in the HSM_ST_LAST state
(indicated by the ATA_FLAG_PIO_POLLING flag) and the ATAPI device
generates CDB interrupts, we have to use the polling PIO protocol.
(Otherwise, the CDB interrupts might confuse the LLDD.)
We just set the protocol to PIO here in ata_check_atapi_dma().
Later in ata_qc_issue_prot(), the PIO protocol will be set as "polling"
for those LLDDs.
Patch against the irq-pio branch +
(1) irq-pio minor fixes (respin) +
(2) integrate polling pio with irq-pio (respin)
Applied, though I think its an open question what happens with
CDB-interrupt ATAPI devices want to do DMA. Perhaps we just get an
interrupt event that we clear, then life proceeds as normal.
Does anybody actually have such a device anywhere? :)
Jeff
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