[PATCH V2 0/4] misc: xgene: Add support for APM X-Gene SoC Queue Manager/Traffic Manager

[Loc Ho]

Hi,

>> >> >> This patch adds support for APM X-Gene SoC Queue Manager/Traffic Manager.
>> >> >>  QMTM is required by APM X-Gene SoC Ethernet, PktDMA (XOR Engine) and
>> >> >>  Security Engine subsystems. All subsystems communicate with QMTM using
>> >> >>  messages which include information about the work to be performed and
>> >> >>  the location of associated data buffers.
>> >> >
>> >> > Please describe here what the purpose of the qmtm is, as this is not
>> >> > entirely clear from the code.
>> >> >
>> >> > In particular, please describe how this differs from a dmaengine driver
>> >> > and why it is not possible to extend the dma slave API to describe qmtm
>> >> > as a dma engine.
>> >> >
>> >> [Loc Ho]
>> >> If the QM driver implements the DMA API, what about the actual DMA
>> >> engine driver which interfaces with this QM driver. We would have DMA
>> >> client interfaces with the X-Gene DMA driver (not available yet) via
>> >> DMA API which in turn interfaces with this QM driver via DMA API.
>> >> Won't this be kind of awkward? Also, the QM only manage messages (or
>> >> descriptors) which are 32-bytes or 64-bytes. It doesn't actually do
>> >> any data transfer of various sizes.
>> >
>> > Please describe here what the purpose of the qmtm is, as this is not
>> > entirely clear from the code or from your reply.
>> >
>> > Greg was guessing that it's a bus controller, my best guess is a DMA
>> > engine. If it's something completely different, you have to let
>> > us know what it is so we can do a proper review rather than guessing.
>> >
>> > Please provide a link to the data sheet if you are unable to explain.
>>
>> Here is URL to a text document explaining role of QMTM device with CPU, Ethernet
>> subsystem.
>>
>> https://drive.google.com/file/d/0B28TgQZ3JLoRRGNnbjJoUGNHWW8/edit?usp=sharing
>
> There is nothing at this link :(

I tried click on the txt file link from web site
http://www.spinics.net/lists/netdev/msg264628.html and don't see any
problem with accessing the txt file.

-Loc