[#5145] SPORT UART hits underflow when flooding
Submitted By: Claudio Cunha
2009-05-19 08:06:35 Close Date
Closed Fixed In Release:
Found In Release:
BF533 Silicon Revision:
Is this bug repeatable?:
Uboot version or rev.:
Toolchain version or rev.:
App binary format:
Summary: SPORT UART hits underflow when flooding
I've reported a bug when we make the link ppp as described in the document
http://docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:ppp in the lauching pppd part.
If I make a ping -f -s 1500 10.0.0.209, a SPORT Error: RX underflow appears, but in the other side (ping -f -s 1500 10.0.0.2) there is no problem.
Look at the file jointed.
--- Mike Frysinger 2009-05-19 08:13:11
please describe your exact hardware setup
--- Claudio Cunha 2009-05-19 08:27:59
It's a board very similar to the Blackfin BF533 Ez-Kit, with sport emulated
uart. And I use the sport0 at 57600 bauds, in the other side there is a pc linux
with usb-serial converter...
--- Mike Frysinger 2009-05-19 08:32:40
forget about ppp/ping. try a simple case like sending/receiving /proc/kallsyms
over the SPORT UART and make sure that works first.
--- maverick gao 2009-05-27 04:23:09
Yes, I meet this problem too. I wrote it in the forum.
--- Sonic Zhang 2009-05-27 05:18:57
Confirmed in SVN trunk.
--- maverick gao 2009-05-29 21:34:23
What does it mean that Confirmed in SVN trunk
--- maverick gao 2009-05-30 21:52:44
I made a mistake that my linux kernel is not 2.4.
It is 22.214.171.124-ADI-2006R1-hhbf and gcc is 3.4.5
processor is BF531, silicon version is 0.5
--- Sonic Zhang 2009-05-31 02:22:54
That means we can replicated it with SVN trunk souce and blackfin developing
--- Sonic Zhang 2009-06-18 06:43:25
This bug is found to occur only when we set sport RX word length to 17 ~ 32
The walkaround by now is warning customer not to use 8-bit uart mode in sport
uart driver. Use 7, 6, 5 bit mode instead.
--- Mike Frysinger 2009-06-18 07:07:52
unless i missed something, CS8 is the default and most common mode people will
be using. telling people not to use it isnt really a workaround.
--- Sonic Zhang 2009-06-18 23:03:50
CS8 can be replaced by 2 CS5 transfer. There is no walk around in CS8 mode.
--- Sonic Zhang 2009-07-17 06:32:57
Disable local interrupt to walk around the fake RX underflow error
when do 32-bit reading from RX fifois interrupted by other interrupt.
This is a possible hardware anomaly. After it is logged officially,
the official anomaly id should be listed bellow.
16-bit reading is not affected.
--- Robin Getz 2010-06-11 14:00:44
Now described in the anomaly sheets now:
Anomaly 05000473 - Interrupted SPORT Receive Data Register Read Results In
Underflow when SLEN > 15
File Name File Type File Size Posted By
pingfloat10.0.0.209.png image/png 323242 Claudio Cunha