On Thu, Oct 06, 2016 at 12:08:26PM +0300, Ville Syrjälä wrote:
> On Thu, Oct 06, 2016 at 10:36:09AM +0300, Felipe Balbi wrote:
> >
> > Hi,
> >
> > Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes:
> <snip>
> > Okay, I have found a regression on dwc3 and another patch follows:
> >
> > commit 5e1a2af3e46248c55098cdae643c4141851b703e
> > Author: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
> > Date: Wed Oct 5 14:24:37 2016 +0300
> >
> > usb: dwc3: gadget: properly account queued requests
> >
> > Some requests could be accounted for multiple
> > times. Let's fix that so each and every requests is
> > accounted for only once.
> >
> > Cc: <stable@xxxxxxxxxxxxxxx> # v4.8
> > Fixes: 55a0237f8f47 ("usb: dwc3: gadget: use allocated/queued reqs for LST bit")
> > Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
> >
> > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > index 07cc8929f271..3c3ced128c77 100644
> > --- a/drivers/usb/dwc3/gadget.c
> > +++ b/drivers/usb/dwc3/gadget.c
> > @@ -783,6 +783,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
> > req->trb = trb;
> > req->trb_dma = dwc3_trb_dma_offset(dep, trb);
> > req->first_trb_index = dep->trb_enqueue;
> > + dep->queued_requests++;
> > }
> >
> > dwc3_ep_inc_enq(dep);
> > @@ -833,8 +834,6 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
> >
> > trb->ctrl |= DWC3_TRB_CTRL_HWO;
> >
> > - dep->queued_requests++;
> > -
> > trace_dwc3_prepare_trb(dep, trb);
> > }
> >
> > @@ -1861,8 +1860,11 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
> > unsigned int s_pkt = 0;
> > unsigned int trb_status;
> >
> > - dep->queued_requests--;
> > dwc3_ep_inc_deq(dep);
> > +
> > + if (req->trb == trb)
> > + dep->queued_requests--;
> > +
> > trace_dwc3_complete_trb(dep, trb);
> >
> > /*
> >
> > I have also built a branch which you can use for testing. Here's a pull
> > request, once you tell me it works for you, then I can send proper
> > patches out:
> >
> > The following changes since commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3:
> >
> > Linux 4.8 (2016-10-02 16:24:33 -0700)
> >
> > are available in the git repository at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git tmp-test-v4.8
> >
> > for you to fetch changes up to c968b8d1effe64a7980802d1eef29f4e1922faca:
> >
> > usb: dwc3: gadget: properly account queued requests (2016-10-06 10:16:37 +0300)
> >
> > ----------------------------------------------------------------
> > Felipe Balbi (2):
> > usb: gadget: function: u_ether: don't starve tx request queue
> > usb: dwc3: gadget: properly account queued requests
> >
> > drivers/usb/dwc3/gadget.c | 7 ++++---
> > drivers/usb/gadget/function/u_ether.c | 5 +++--
> > 2 files changed, 7 insertions(+), 5 deletions(-)
>
> Tried your branch, but unfortunately I'm still seeing the lags. New trace
> attached.
Just a reminder that the regressions is still there in 4.9-rc2.
Unfortunateyly with all the stuff already piled on top, getting USB
working on my device is no longer a simple matter of reverting the
one commit. I had to revert 10 patches to get even a clean revert, but
unfortunately that approach just lead to the transfer hanging immediately.
So what I ended up doing is reverting all of this:
git log --no-merges --format=oneline 55a0237f8f47957163125e20ee9260538c5c341c^..HEAD -- drivers/usb/dwc3/ include/linux/ulpi/interface.h drivers/usb/Kconfig drivers/usb/core/Kconfig
which comes out at whopping 70 commits. Having to carry that around
is going to be quite a pain especially as more stuff might be piled on
top.
/me thinks a stable backport of any fix (assuming one is found
eventually) is going to be quite the challenge...
--
Ville Syrjälä
Intel OTC
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