[Emc-developers] jepler/hm2-eth-multiple: support multiple hostmot2 ethernet cards

[Jeff Epler]

Peter noticed that introducing a gigabit switch between PC and hostmot2
ethernet card had only a small impact on latency and servo thread
execution time, and there's plenty of bandwidth available between the PC
and the switch.

So this weekend I implemented support for multiple hostmot2 ethernet
cards. In theory, multiple NICs are supported as well as multiple cards
on one nic via a switch, but I only tested the latter.

My testing setup:
pci-e gigabit nic -- $25 gigabit switch -- 7i80hd
(Intel 82574L) -- 7i80db
-- 7i90

My testing setup, which can run 1 card at 2kHz, seems to run 3 cards at
1.25kHz, though it's only been going for a few hours.

One bug fix will be coming soon: if you configure 2 7i80 and 1 7i92, the
hal names should start
hm2_7i80.0
hm2_7i80.1
hm2_7i92.0
but right now the last one comes up as
hm2_7i92.2

[andy pugh]

Post by Jeff Epler
One bug fix will be coming soon: if you configure 2 7i80 and 1 7i92, the
hal names should start
hm2_7i80.0
hm2_7i80.1
hm2_7i92.0
but right now the last one comes up as
hm2_7i92.2

There is an option to index the smart-serial devices by the last 4 digits
of their serial number (which is on a sticker on the card). I can't recall
(and I am working away from home) where that tag goes, but if it is in the
loadrt hostmot2 line, then perhaps that would be an option here too?

[Jeff Epler]

I updated the branch slightly.

The following changes since commit 641e98acefe8619faf23bb94e1e5f24b4cfc171a:

uspace: must advise user to set RTAPI_FIFO_PATH (2015-07-15 20:08:51 -0500)

are available in the git repository at:

git://git.linuxcnc.org/git/linuxcnc.git jepler/hm2-eth-multiple

for you to fetch changes up to 7be45d776c9b109dc29fed466fa1da411263a9ef:

hm2_eth: make unrecognized boards work (2015-07-15 20:16:24 -0500)

----------------------------------------------------------------
Jeff Epler (4):
hm2_eth: allow multiple instances (up to 4)
hostmot2: support split reads
hm2_eth: in case of failed recv(), show an error
hm2_eth: make unrecognized boards work

docs/man/man9/hm2_eth.9 | 2 -
docs/man/man9/hostmot2.9 | 14 +
src/hal/drivers/mesa-hostmot2/hm2_eth.c | 320 ++++++++++++++-------
src/hal/drivers/mesa-hostmot2/hm2_eth.h | 29 +-
src/hal/drivers/mesa-hostmot2/hostmot2-lowlevel.h | 7 +
src/hal/drivers/mesa-hostmot2/hostmot2.c | 33 ++-
src/hal/drivers/mesa-hostmot2/hostmot2.h | 1 +
src/hal/drivers/mesa-hostmot2/tram.c | 11 +-
8 files changed, 295 insertions(+), 122 deletions(-)