usb: dwc3: gadget: Properly initialize LINK TRB

On ISOC endpoints the last trb_pool entry used as a
LINK TRB is not getting zeroed out correctly due to
memset being called incorrectly and in the wrong place.
If pool allocated from DMA was not zero-initialized
to begin with this will result in the size and ctrl
values being random garbage. Call memset correctly after
assignment of the trb_link pointer.

Fixes: f6bafc6a1c ("usb: dwc3: convert TRBs into bitshifts")
Cc: <stable@vger.kernel.org> # v3.4+
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index f6d1dbafa2988bd7db6006aa488d037371b79ee2..546ea5431b8cd225165b38ca0e5ff2b53906738c 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -525,12 +525,11 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
                if (!usb_endpoint_xfer_isoc(desc))
                        return 0;
 
-               memset(&trb_link, 0, sizeof(trb_link));
-
                /* Link TRB for ISOC. The HWO bit is never reset */
                trb_st_hw = &dep->trb_pool[0];
 
                trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
+               memset(trb_link, 0, sizeof(*trb_link));
 
                trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
                trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));