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

[Mark Lord <liml@rtr.ca>]

Albert Lee wrote:
> Jeff Garzik wrote:
> 
>> 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.
> 
> Not sure. I have no such device at hand for test; currently relying
> on the SFF-8020i spec (http://www.bswd.com/sff8020i.pdf) as reference.
> According to p.31, we have to send out the CDB after receiving
> the CDB interrupt. So, just clearing the irq looks not enough.
> 
>> Does anybody actually have such a device anywhere?  :)
> 
> Maybe Alan or Mark knows? 
> 
> We really need tester for such device.

hdparm identifies them with "-I", but libata doesn't allow HDIO_DRIVE_CMD
on ATAPI (yet?), and I've not yet updated hdparm to use SGIO directly.

But I did have such devices here once, like this one below,
from my library of IDENTIFY dumps:

 >ATAPI CD-ROM, with removable media
 >        Model Number:       CD-ROM 36X/AKU
 >        Serial Number:
 >        Firmware Revision:  U10I
 >Standards:
 >        Used: ATAPI for CD-ROMs, SFF-8020i, r2.5
 >        Supported: CD-ROM ATAPI-1
 >Configuration:
 >        DRQ response: <=10ms with INTRQ
 >        Packet size: 12 bytes
...

MMmm.. there's even a drive on the shelf here that might
be that exact unit.  I'll plug it in and see if it is.

-ml