diff options
| author | Aleksander Morgado <aleksander@aleksander.es> | 2015-03-06 17:14:21 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-06 09:47:48 -0800 |
| commit | 45ba2154d12fc43b70312198ec47085f10be801a (patch) | |
| tree | 997ed7d9e65110163e50ef78633eacd9f24c48e0 /drivers/usb/host/xhci.h | |
| parent | d3d5389475e8554842ec5640e1e0e93a298f2680 (diff) | |
xhci: fix reporting of 0-sized URBs in control endpoint
When a control transfer has a short data stage, the xHCI controller generates
two transfer events: a COMP_SHORT_TX event that specifies the untransferred
amount, and a COMP_SUCCESS event. But when the data stage is not short, only the
COMP_SUCCESS event occurs. Therefore, xhci-hcd must set urb->actual_length to
urb->transfer_buffer_length while processing the COMP_SUCCESS event, unless
urb->actual_length was set already by a previous COMP_SHORT_TX event.
The driver checks this by seeing whether urb->actual_length == 0, but this alone
is the wrong test, as it is entirely possible for a short transfer to have an
urb->actual_length = 0.
This patch changes the xhci driver to rely on a new td->urb_length_set flag,
which is set to true when a COMP_SHORT_TX event is received and the URB length
updated at that stage.
This fixes a bug which affected the HSO plugin, which relies on URBs with
urb->actual_length == 0 to halt re-submitting the RX URB in the control
endpoint.
Cc: <stable@vger.kernel.org>
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/xhci.h')
| -rw-r--r-- | drivers/usb/host/xhci.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 3b97f0582155..d0663931e5ba 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1,3 +1,4 @@ + /* * xHCI host controller driver * @@ -1291,6 +1292,8 @@ struct xhci_td { struct xhci_segment *start_seg; union xhci_trb *first_trb; union xhci_trb *last_trb; + /* actual_length of the URB has already been set */ + bool urb_length_set; }; /* xHCI command default timeout value */ |