Re: [PATCH 1/1] libata-dev: ata_check_atapi_dma() fix for ATA_FLAG_PIO_POLLING LLDDs

[Jeff Garzik <jgarzik@pobox.com>]

Albert Lee wrote:
> ata_check_atapi_dma() fix for LLDDs with the ATA_FLAG_PIO_POLLING flag.
> 
> Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
> ---
> 
> 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