usb: dwc3: gadget: Properly initialize LINK TRB

commit 1200a82a59b6aa65758ccc92c3447b98c53cd7a2 upstream.

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")
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index d868b62c1a16586355197dc1f9c7a0191e7fc264..ec4cb05291d7ee9dbdae7df57e46c0b8a5214579 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -550,12 +550,11 @@ 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));