2013/5/23 Alan Ott <a...@signal11.us>: > On 5/22/13 4:32 PM, David Hauweele wrote: >> >> I cannot use level-triggered interrupts with GPIO on the RPi, so I >> cannot test this specific patch. > > > Is there another interrupt line you can tie into which does support > level-trigger interrupts (INT0 or something)?
According to the datasheet it should be possible but the bcm2708 port does not support it. I've been told that we shouldn't use level-triggered interrupts in the first place. > > >> However I agree with the idea of level-triggered interrupts, that >> would fix all major problems related to missed interrupts. >> >> Beside this I'm running a ping -f since more than two hours now and it >> seems to work well. >> > > So that surprises me. I thought level-trigger interrupts were the thing that > would fix this problem, and if you're not running with that patch, you just > have the INIT_COMPLETION() fix (which you said didn't fix your issue) and > the threaded interrupts patch, which I was fairly sure I had determined > wasn't fixing any actual race-condition-related problems. I should have been more clear about this. I've tested [PATCH 1/3] which fixes the race condition with tx_complete. That is the INIT_COMPLETION() fix. But it is still possible to miss an interrupt, perhaps it just took longer this time. I ran the test again today and it failed after 30 minutes. I did not test [PATCH 2/3], that is the threaded IRQ. Instead I removed interrupt enable/disable from the IRQ handler and the workqueue. Without this the driver would fail within seconds of a ping -f. Have you observed this too ? Perhaps this problem is specific to the bcm2708 port. David > > I'm glad, but surprised that you're no longer seeing issues. > > Alan. > > >> >> 2013/5/22 Alan Ott <a...@signal11.us>: >>> >>> On 05/21/2013 10:01 PM, Alan Ott wrote: >>>> >>>> David Hauweele noticed that the mrf24j40 would hang arbitrarily after >>>> some >>>> period of heavy traffic. Two race conditions were discovered, and the >>>> driver was changed to use threaded interrupts, since the enable/disable >>>> of >>>> interrupts in the driver has recently been a lighning rod whenever >>>> issues >>>> arise related to interrupts (costing engineering time), and since >>>> threaded >>>> interrupts are the right way to do it. >>>> >>>> Alan Ott (3): >>>> mrf24j40: Move INIT_COMPLETION() to before packet transmission >>>> mrf24j40: Use threaded IRQ handler >>>> mrf24j40: Use level-triggered interrupts >>>> >>>> drivers/net/ieee802154/mrf24j40.c | 31 +++++++++---------------------- >>>> 1 file changed, 9 insertions(+), 22 deletions(-) >>> >>> >>> I forgot to add, I ran ping -f both ways all afternoon (6.5 hours), and >>> it seems solid. >>> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
