[PATCH 4.19 05/46] usb: dwc3: gadget: Do link recovery for SS and SSP

From: Greg Kroah-Hartman
Date: Fri May 01 2020 - 09:53:39 EST


From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

commit d0550cd20e52558ecf6847a0f96ebd5d944c17e4 upstream.

The controller always supports link recovery for device in SS and SSP.
Remove the speed limit check. Also, when the device is in RESUME or
RESET state, it means the controller received the resume/reset request.
The driver must send the link recovery to acknowledge the request. They
are valid states for the driver to send link recovery.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
Fixes: ee5cd41c9117 ("usb: dwc3: Update speed checks for SuperSpeedPlus")
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/dwc3/gadget.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1577,7 +1577,6 @@ static int __dwc3_gadget_wakeup(struct d
u32 reg;

u8 link_state;
- u8 speed;

/*
* According to the Databook Remote wakeup request should
@@ -1587,16 +1586,13 @@ static int __dwc3_gadget_wakeup(struct d
*/
reg = dwc3_readl(dwc->regs, DWC3_DSTS);

- speed = reg & DWC3_DSTS_CONNECTSPD;
- if ((speed == DWC3_DSTS_SUPERSPEED) ||
- (speed == DWC3_DSTS_SUPERSPEED_PLUS))
- return 0;
-
link_state = DWC3_DSTS_USBLNKST(reg);

switch (link_state) {
+ case DWC3_LINK_STATE_RESET:
case DWC3_LINK_STATE_RX_DET: /* in HS, means Early Suspend */
case DWC3_LINK_STATE_U3: /* in HS, means SUSPEND */
+ case DWC3_LINK_STATE_RESUME:
break;
default:
return -EINVAL;