Re: [PATCH v2 1/3] dmaengine: add new dma API for max_segment_number
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Date: 2011-06-08 05:24:22
Also in:
linux-arm-kernel, lkml
On Mon, 6 Jun 2011 11:48:56 -0700 Dan Williams [off-list ref] wrote:
dmaengine expands the class of dma providers to include standalone dma agents on a host bus (or elsewhere) in addition to the traditional bus mastering host-bus-adapters that the existing api understands. So in the case of slave dma the dma capabilities of the block-device are irrelevant because another agent will do the transfer on behalf of the block-device driver. So the value should be whatever the dma device driver says it is.
The dma parameter restriction could be due to software (HBA drivers, or subsystem). The value should be whatever the dma device driver says it is in such case?