On Sat, Jan 04, 2014 at 09:39:08PM -0800, Loc Ho wrote: > 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. Now it's working :) Anyway, as this is a .txt file, why wasn't it just sent in email, and added to the patch series as a documentation file? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
