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authorAlan Stern <stern@rowland.harvard.edu>2014-07-18 16:26:17 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-18 16:34:29 -0700
commit499b3803d3e2f062f73bf22372b38393369ffcbf (patch)
tree4f33ecaf596af157df8a4cdccbf1fd2ea5f6e3f0 /drivers/usb/host/ohci.h
parent81e38333513cec155c720432226dabe9f9f76a77 (diff)
downloadlinux-499b3803d3e2f062f73bf22372b38393369ffcbf.tar.gz
USB: OHCI: add check for stopped frame counter
This patch adds an extra check to ohci-hcd's I/O watchdog routine.  If
the controller stops updating the frame counter, we will assume it is
dead.  But there has to be an exception: Some controllers stop the
frame counter when no ports are connected.  Check to make sure there
is at least one active port before deciding the controller is dead.

(This test may appear racy, but it isn't.  Enabling a newly connected
port takes several milliseconds, during which time the frame counter
must advance.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Dennis New <dennisn@dennisn.linuxd.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ohci.h')
-rw-r--r--drivers/usb/host/ohci.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 0548f5ca18e2..59f424567a8d 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -421,6 +421,7 @@ struct ohci_hcd {
 
 	// there are also chip quirks/bugs in init logic
 
+	unsigned		prev_frame_no;
 	unsigned		wdh_cnt, prev_wdh_cnt;
 	u32			prev_donehead;
 	struct timer_list	io_watchdog;