| From c66f59ee5050447b3da92d36f5385a847990a894 Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Micha=C5=82=20Pecio?= <michal.pecio@gmail.com> |
| Date: Tue, 7 Jun 2016 12:34:45 +0200 |
| Subject: USB: OHCI: Don't mark EDs as ED_OPER if scheduling fails |
| |
| From: Michał Pecio <michal.pecio@gmail.com> |
| |
| commit c66f59ee5050447b3da92d36f5385a847990a894 upstream. |
| |
| Since ed_schedule begins with marking the ED as "operational", |
| the ED may be left in such state even if scheduling actually |
| fails. |
| |
| This allows future submission attempts to smuggle this ED to the |
| hardware behind the scheduler's back and without linking it to |
| the ohci->eds_in_use list. |
| |
| The former causes bandwidth saturation and data loss on isoc |
| endpoints, the latter crashes the kernel when attempt is made |
| to unlink such ED from this list. |
| |
| Fix ed_schedule to update ED state only on successful return. |
| |
| Signed-off-by: Michal Pecio <michal.pecio@gmail.com> |
| Acked-by: Alan Stern <stern@rowland.harvard.edu> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/usb/host/ohci-q.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/usb/host/ohci-q.c |
| +++ b/drivers/usb/host/ohci-q.c |
| @@ -183,7 +183,6 @@ static int ed_schedule (struct ohci_hcd |
| { |
| int branch; |
| |
| - ed->state = ED_OPER; |
| ed->ed_prev = NULL; |
| ed->ed_next = NULL; |
| ed->hwNextED = 0; |
| @@ -259,6 +258,8 @@ static int ed_schedule (struct ohci_hcd |
| /* the HC may not see the schedule updates yet, but if it does |
| * then they'll be properly ordered. |
| */ |
| + |
| + ed->state = ED_OPER; |
| return 0; |
| } |
| |
