On 23.9.2019 10.08, alex zheng wrote:
Hi, balbi,
Thank you for your reply~
Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> 于2019年9月23日周一 下午1:36写道：
Hi,
(it helps when you Cc correct maintainers ;-)
alex zheng <tc0721@xxxxxxxxx> writes:
Hi all,
I am a user of dwc3 USB host controller, I found there are some
confused behavior of trb event on this controller.
When I run a raw USB data transfer(run bulk in&out transfer with
libusb) and iperf3(over rndis) at the same time,
there are some strange interrupts occurs and make the driver report
error(ERROR DMA transfer).
And:
So dwc3 is workingo n host mode. Which platform is this?
This is our self-design platform (ARM v7 cpu core with synopsys DWC
USB3.0 controller).
version info: Linux localhost 4.9.130-645692-g6ecde01-dirty #394 SMP
PREEMPT Sun Sep 22 15:10:51 CST 2019 armv7l
1. this problem only hapened in USB SS mode
2. this problem seems not hapen when I run same test case with other
xhci controller(such as asmedia/intel pcie xhci controller) on PC.
3. the kernel version is 4.9.130
Have you tried a more recent kernel? 4.9 is really ancient. Please try
v5.3.
Our platform only support 4.9 kernel now, and it may take a lot of
work to do to support the recent kernel.
Are there any causes may lead the link TRB trigger a interrupt when
the IOC bit is not setted?
I think this may be a hw bug of DWC3 USB controller, could anyone
please give me some help to debug this problem？
The detail log see as below:
[ 131.074102] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto: xHCI
handle event, 8000
27630 [ 131.074109] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
process trans event : ep_index = 11, event_dma = 1eb13e90
27631 [ 131.074117] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
inc_deq, start trb dma = 1eb13e90, dequeue_p = e482ce90, trb_free num
= 1871, ring type = 2
27632 [ 131.074123] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
inc_deq 111, start trb dma = 1eb13ea0, dequeue_p = e482cea0, trb_free
num = 1872, ring type = 2
27633 [ 131.074130] c0 3 (ksoftirqd/0) xhci-hcd xh[ 133.057617] c0 3
(ksoftirqd/0) xhci-hcd xhci-hcd.0.auto: ERROR Transfer event TRB DMA
ptr not part of current TD ep_index 16 comp_code 1
27634 [ 133.059312] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb0fff0 trb-start 000000001eb10000
trb-end 000000001eb10000 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27635 [ 133.066215] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
27636 [ 133.067908] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb10000 trb-start 000000001eb10230
trb-end 000000001eb10230 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27637 [ 133.070572] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
27638 [ 133.072260] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb10010 trb-start 000000001eb10230
trb-end 000000001eb10230 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27639 [ 133.075052] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
27640 [ 133.076739] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb10020 trb-start 000000001eb10230
trb-end 000000001eb10230 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27641 [ 133.079472] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
27642 [ 133.081159] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb10030 trb-start 000000001eb10230
trb-end 000000001eb10230 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27643 [ 133.083896] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
27644 [ 133.085584] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
Looking for event-dma 000000001eb10040 trb-start 000000001eb10230
trb-end 000000001eb10230 seg-start 000000001eb10000 seg-end
000000001eb10ff0
27645 [ 133.088328] c0 3 (ksoftirqd/0) xhci-hcd xhci-hcd.0.auto:
ERROR Transfer event TRB DMA ptr not part of current TD ep_index 16
comp_code 1
1. According these logs above the link trb whose address is 0x1eb0fff0
occurs a transfer event, but this DMA address is not in the trb ring,
then the driver report an error(and followed a few error logs witch
invalid DMA address).
To me it looks like the controller creates an extra successful transfer event
for the Link TRB.
The link TRB DMA that the event is pointing to is part of the ring, but not part
of next Transfer Descriptor (TD) xhci driver expects to handle.
The link TRB is the last TRB of the previous ring segment, The TD the xhci driver
expects is on the next segment.
2. I dump the data of the address(0x1eb0fff0) and find the IOC bit is
not set, see as below:
# dump_reg.sh 0x1eb0fff0 4
0x1eb0fff0:0x1EB10000 0x00000000 0x00000000 0x00001800
The link TRB looks fine. TRB typeis link, and its next segment pointer is 0x1eb10000,
which is also where driver was expecting the next TD to be found.
No other bits are set.
Does everything work normally if you just ignore that error?
Can be done with a hack like this (untested):
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 40fa25c4d041..d5f4c416d0ef 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2531,7 +2531,8 @@ static int handle_tx_event(struct xhci_hcd *xhci,
trb_in_td(xhci, ep_ring->deq_seg,
ep_ring->dequeue, td->last_trb,
ep_trb_dma, true);
- return -ESHUTDOWN;
+ xhci_err(xhci, "Ignoring error\n");
+ goto cleanup;
}
skip_isoc_td(xhci, td, event, ep, &status);
-Mathias
