On Sun, Jan 5, 2014 at 10:01 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > 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? Sure I will include the text documentation to an appropriate place in the Documentation directory in my next version of QMTM patch. -- 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
