libata-sff: Fix documentation

Code moved to ioread/iowrite but the comment didn't
Also note a posting issue

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Alan Cox 2007-09-20 15:03:07 +01:00 committed by Jeff Garzik
parent 0e3dbc01d5
commit e1cc9de836

View File

@ -297,7 +297,7 @@ void ata_bmdma_start (struct ata_queued_cmd *qc)
dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
/* Strictly, one may wish to issue a readb() here, to
/* Strictly, one may wish to issue an ioread8() here, to
* flush the mmio write. However, control also passes
* to the hardware at this point, and it will interrupt
* us when we are to resume control. So, in effect,
@ -307,6 +307,9 @@ void ata_bmdma_start (struct ata_queued_cmd *qc)
* is expected, so I think it is best to not add a readb()
* without first all the MMIO ATA cards/mobos.
* Or maybe I'm just being paranoid.
*
* FIXME: The posting of this write means I/O starts are
* unneccessarily delayed for MMIO
*/
}