[PATCH] usb: dwc3: core: Fix broken system suspend/resume on AM437x

From: Roger Quadros
Date: Fri Mar 16 2018 - 10:44:40 EST


On TI's AM437x, the DWC3 controller looses state after a
system suspend/resume. We are re-initializing the controller
but we miss restoring the PRTCAP register. This causes
USB host to break on AM437x after a system suspend/resume.

Fix this by restoring the PRTCAP register on system resume.

Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
drivers/usb/dwc3/core.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index e8890c0..5becd7f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1374,6 +1374,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
if (ret)
return ret;

+ dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_resume(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
@@ -1384,6 +1385,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
ret = dwc3_core_init(dwc);
if (ret)
return ret;
+ dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
}
break;
case DWC3_GCTL_PRTCAP_OTG:
--
cheers,
-roger

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