Carlos Pardo wrote: > The 3611 bridge does not support the ATAPI DMA direction bit in hardware.(software support only) > > The 3811 bridge supports ATAPI DMA direction bit in both software and hardware. > > The 646 chip is ancient and he should upgrade. The behavior of this device is unknown since this part was EOL'd years ago. > > Hi Carlos, Does this mean that only the 3611 bridge needs the DMA_DIR bit set by host software, while 3811 can detect the ATAPI DMA direction by hardware and doesn't need the DMA_DIR bit? (I guess that 3811 detects the direction by looking into the SCSI CDB. If the SCSI command is unknown to it, 3811 still needs the DMA_DIR bit set by software.) Is there anyway that we could detect whether the DMA_DIR needs to be set by host software? Is there anyway that we could detect whether the bridge is a 3611 or a 3811 chip automatically? Per Jeff's comment, there is a document on t13 (http://www.t13.org/docs2003/e03131r0.pdf). The documents reads: "Eg. – Word 50, bit 13: Set to 1 for devices that support DMAIN bit in Features Register for Packet Command". However, this looks more for the ATAPI device than for the bridge? Also it looks not a t13 standard yet? Can we use this word 50 to identify 3611/3811? Thanks, Albert - : send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
