diff options
| author | Amit Virdi <amit.virdi@st.com> | 2015-01-13 14:27:20 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-27 08:18:56 -0800 |
| commit | 0f1f031c46c984faeeca6d6d0adb7d11c2da3ced (patch) | |
| tree | a52321b89a32e79a4383f6e252054d9545b6885d | |
| parent | 5cb2226deeb4ed98520ae2c5e6746daf62d99bd1 (diff) | |
usb: dwc3: gadget: Fix TRB preparation during SG
commit ec512fb8e5611fed1df2895f90317ce6797d6b32 upstream.
When scatter gather (SG) is used, multiple TRBs are prepared from one DWC3
request (dwc3_request). So while preparing TRBs, the 'last' flag should be set
only when it is the last TRB being prepared from the last dwc3_request entry.
The current implementation uses list_is_last to check if the dwc3_request is the
last entry from the request_list. However, list_is_last returns false for the
last entry too. This is because, while preparing the first TRB from a request,
the function dwc3_prepare_one_trb modifies the request's next and prev pointers
while moving the URB to req_queued. Hence, list_is_last always returns false no
matter what.
The correct way is not to access the modified pointers of dwc3_request but to
use list_empty macro instead.
Fixes: e5ba5ec833aa (usb: dwc3: gadget: fix scatter gather implementation)
Signed-off-by: Amit Virdi <amit.virdi@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index d90c70c23adb..f4ca19f15876 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -887,8 +887,7 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting) if (i == (request->num_mapped_sgs - 1) || sg_is_last(s)) { - if (list_is_last(&req->list, - &dep->request_list)) + if (list_empty(&dep->request_list)) last_one = true; chain = false; } |