[PATCH 3.12 154/206] usb: dwc3: gadget: Properly initialize LINK TRB

[Jiri Slaby]

From: Jack Pham <jackp@xxxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

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@xxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/usb/dwc3/gadget.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c37da0c9a076..2cdf69962e31 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -532,12 +532,11 @@ 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));
-- 
2.1.3

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