[PATCH 3.13 136/162] usb: dwc3: gadget: Properly initialize LINK TRB

From: Kamal Mostafa
Date: Thu Nov 06 2014 - 18:16:01 EST


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

------------------

From: Jack Pham <jackp@xxxxxxxxxxxxxx>

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: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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 27b9c8a..20e4d2e 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));
--
1.9.1

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