Tony,
On 2017-05-06 01:55, Tony Lindgren wrote:
OK I verified that with the current mainline kernel using dma
and g_ether and your patches 1 to 3 I can run the variable size
ping test loop for few minutes before it just stops working and
I can see the legacy DMA interrupt increase depending on the
size of the packet. Then I checked with v4.1 kernel, and that
too seems to have the same issue.
I've also verified running the same variable size ping test with
your patch 4/4 makes things stop within just a few seconds. The
script I'm using for ping is below.
Anyways, what we really should ensure here is that the external
dmarequest line is properly triggering things with dmaengine :)
That's why I'm a bit worried your patch 4/4.
Oh and I also verified the GPMC timings we're using are the same
as in production n810 kernel so that should not be the issue.
And using the async access on n800 will not work as it will
produce corrupt transfer size register the report I posted
earlier is from n800 allowing it to use async transfers. On
n810 async transfers may work as I recall it having a newer
tusb6010 version.
I think I have nailed the issue. I had a bug in the omap-dma
implementation of the port_window (sigh) and couple of issues in the
tusb6010/*_omap, not introduced by the series.
The ASYNC access is pretty unstable on n810 as well, I got corruption in
the XFR_SIZE.
I have been using the g_ncm gadget with
"musb->g.quirk_avoids_skb_reserve = 1;" to ensure that we are using SYNC
access.
I'm running your variable ping script for 2 hours now, it wrapped >130
times already, I also run a standalone ping with 2048 size in parallel,
the n810 is booted to nfsroot:
# cat /proc/interrupts | grep dma
29: 9483598 INTC 13 Edge omap-dma-engine
#
I need to clean up the code as I had debugs (disabled now) and stuff and
I want to try the tusb6010 changes w/o the DMAengine conversion.
Regards,
Tony
8< ----------------
#!/bin/bash
device=$1
size=$2
+ wraps = 0
while [ 1 ]; do
#echo "Pinging with size $size"
if ! ping -w0 -c1 -s$size $device > /dev/null 2>&1; then
break;
fi
size=$(expr $size + 1)
if [ $size -gt 8192 ]; then
+ wraps=$(expr $wraps + 1)
+ echo "wrapping ($wraps) at $size"
size=1
fi
done
echo "Test ran up to $size"
- Péter
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