USB: OHCI: don't lose track of EDs when a controller dies
commit 977dcfdc60311e7aa571cabf6f39c36dde13339e upstream.
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
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 <firstname.lastname@example.org>
Signed-off-by: Greg Kroah-Hartman <email@example.com>
[bwh: Backported to 3.2: keep using HC_IS_RUNNING()]
Signed-off-by: Ben Hutchings <firstname.lastname@example.org>
1 file changed