Mikael Pettersson wrote:
This patch (against libata #upstream + the ATAPI cleanup patch)
reimplements sata_promise's ATAPI support to format ATAPI DMA
commands as normal packets, and to issue them via the hardware's
normal packet machinery.
It turns out that the only reason for issuing ATAPI DMA
commands via the pdc_issue_atapi_pkt_cmd() procedure was to
perform two interrupt-fiddling steps for ATA_DFLAG_CDB_INTR
devices. But these steps aren't needed because sata_promise
sets ATA_FLAG_PIO_POLLING, which disables DMA for those devices.
The remaining steps can easily be done in ATA taskfile packets.
Concrete changes:
- pdc_atapi_dma_pkt() is extended to program all packet setup
steps, and not just contain the CDB; the sequence of steps
exactly mirrors what pdc_issue_atapi_pkt_cmd() did
- pdc_atapi_dma_pkt() needed more parameters: simplify it by
just passing 'qc' and having it extract the data it needs
- pdc_issue_atai_pkt_cmd() and its two helper procedures
pdc_wait_for_drq() and pdc_wait_on_busy() are removed
Tested on first- and second-generation chips, SATAPI and PATAPI,
with no observable regressions.
Signed-off-by: Mikael Pettersson <mikpe@xxxxxxxx>
Applied patches 1-2.
ATAPI handling looks _so_ much better, now that you're using packets,
doesn't it? :)
Jeff
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