Re: kern/50278: umidi(4) loses first incoming message after second open

[Andreas Gustafsson <gson%gson.org@localhost>]

The following reply was made to PR kern/50278; it has been noted by GNATS.

From: Andreas Gustafsson <gson%gson.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: Nick Hudson <nick.hudson%gmx.co.uk@localhost>
Subject: Re: kern/50278: umidi(4) loses first incoming message after second open
Date: Thu, 28 Nov 2019 11:34:24 +0200

 I have found the cause of the problem in the OHCI case: the toggle
 carry gets reset in ohci_abort_xfer() when the MIDI device is closed
 as the test program exits for the first time.  The following patch
 fixes it.  It's similar to the patch in PR 54070, but applies to
 ohci_abort_xfer() rather than ohci_softintr().
 
 Index: ohci.c
 ===================================================================
 RCS file: /bracket/repo/src/sys/dev/usb/ohci.c,v
 retrieving revision 1.290
 diff -u -r1.290 ohci.c
 --- ohci.c	11 Aug 2019 22:55:03 -0000	1.290
 +++ ohci.c	28 Nov 2019 08:57:02 -0000
 @@ -2348,7 +2348,9 @@
  	if (hit) {
  		DPRINTFN(1, "set hd=0x%08jx, tl=0x%08jx",  (int)p->physaddr,
  		    (int)O32TOH(sed->ed.ed_tailp), 0, 0);
 -		sed->ed.ed_headp = HTOO32(p->physaddr); /* unlink TDs */
 +		/* unlink TDs, preserving toggle carry */
 +		sed->ed.ed_headp = HTOO32(p->physaddr |
 +		    (O32TOH(sed->ed.ed_headp) & OHCI_TOGGLECARRY));
  		usb_syncmem(&sed->dma,
  		    sed->offs + offsetof(ohci_ed_t, ed_headp),
  		    sizeof(sed->ed.ed_headp),
 
 -- 
 Andreas Gustafsson, gson%gson.org@localhost