IDE changes that affect upper layer drivers

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Mon Jan 06 2003 - 18:24:38 EST


I'm about to enable the vmda logic for non disk drivers. That means IDE
tape, scsi, cd and friends need updating to follow the new rules

Before it was simply:
        ->dma = 1 - do DMA

Some devices and a lot of upcoming ones support DMA to the host while
doing PIO to the device "Virtual DMA". That means the drivers now
need to do

        DMA VDMA
         0 X PIO
         1 0 Issue PIO commands, set up for DMA xfers
         1 1 Issue DMA commands, set up for DMA xfers

Alan

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Tue Jan 07 2003 - 22:00:33 EST