Re: [PATCH] Address USB abort races

[Nick Hudson <nick.hudson%gmx.co.uk@localhost>]

On 17/12/2019 04:34, Taylor R Campbell wrote:
> The attached change set aims to fix a number of races in the USB
> transfer complete/abort/timeout protocol by consolidating the logic to
> synchronize it into a few helper subroutines.  (Details below.)
> Bonus: It is no longer necessary to sleep (other than on an adaptive
> mutex) when aborting.

Thanks for working on this.

Some questions/comments if I may

- Any reason that dwc2 and ahci didn't get the conversion? At least dwc2
  should be done - I'm not sure ahci ever worked, but I've tried to keep
  it up-to-date in the past.  slhci probably needs some love too.

- It appears to me that upm_abort could be removed in favour of
  ubm_abortx and all the xfer cancel logic contained there, but that
  could be a future change

- Off list you mentioned ohci getting stuck during testing and I would
  agree it's unlikely that these diffs caused the issue.  I have some
  changes to ohci aborting on nhusb which I'll try and fixup when this
  diff goes in.

Thanks,
Nick