kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-09-26 18:16:26 +00:00
Code Issues Releases Packages Activity

USB: OHCI: don't lose track of EDs when a controller dies

Browse source 
This patch fixes a bug in ohci-hcd.  When an URB is unlinked, the
corresponding Endpoint Descriptor is added to the ed_rm_list and taken
off the hardware schedule.  Once the ED is no longer visible to the
hardware, finish_unlinks() handles the URBs that were unlinked or have
completed.  If any URBs remain attached to the ED, the ED is added
back to the hardware schedule -- but only if the controller is
running.

This fails when a controller dies.  A non-empty ED does not get added
back to the hardware schedule and does not remain on the ed_rm_list;
ohci-hcd loses track of it.  The remaining URBs cannot be unlinked,
which causes the USB stack to hang.

The patch changes finish_unlinks() so that non-empty EDs remain on
the ed_rm_list if the controller isn't running.  This requires moving
some of the existing code around, to avoid modifying the ED's hardware
fields more than once.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Stern 2014-07-17 16:34:29 -04:00 • committed by Greg Kroah-Hartman
commit 977dcfdc60
1 changed files with 29 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files