[PATCH 13/15] usb: dwc3: gadget: prevent DCTL register corruption

[Felipe Balbi <balbi@xxxxxx>]

If we don't read out the contents of the register
(in order to reinitialize 'reg' variable) we will
be writing unknown contents to the DCTL register
whenever we try to use dwc3_gadget_wakeup() function.

Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
 drivers/usb/dwc3/gadget.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0404833..867c476 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1307,6 +1307,7 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g)
 	/* Recent versions do this automatically */
 	if (dwc->revision < DWC3_REVISION_194A) {
 		/* write zeroes to Link Change Request */
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 		reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
 		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
 	}
-- 
1.7.10.2

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