diff options
| author | Amit Virdi <amit.virdi@st.com> | 2015-01-13 11:57:20 +0300 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2015-01-14 20:28:23 +0300 |
| commit | ec512fb8e5611fed1df2895f90317ce6797d6b32 (patch) | |
| tree | 9c157dbcf904459896018942212d8ed559534a3e /drivers/usb | |
| parent | 90bdf403db4ca75ee60ca5a760dc342cef96b5e1 (diff) | |
| download | linux-ec512fb8e5611fed1df2895f90317ce6797d6b32.tar.xz | |
usb: dwc3: gadget: Fix TRB preparation during SG
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>
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb')
| -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 f03b136ecfce..0eec2e917994 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -882,8 +882,7 @@ 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; } |