usb: dwc3: gadget: Fix controller timeout at dwc3_gadget_suspend()
Commit Message
If gadget driver is loaded and we are connected to a USB host,
all transfers must be stopped before stopping the controller else
we will not get a clean stop i.e. dwc3_gadget_run_stop() will take
several seconds to complete and will return -ETIMEDOUT. Fix this.
No need to stop the controller at dwc3_gadget_suspend() if
dwc->softconnect is 0 as controller is already stopped.
Handle error cases properly in dwc3_gadget_suspend().
Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Roger Quadros <rogerq@kernel.org>
---
drivers/usb/dwc3/gadget.c | 69 ++++++++++++++++++++-------------------
1 file changed, 35 insertions(+), 34 deletions(-)
Comments
On Fri, Apr 28, 2023, Roger Quadros wrote:
> If gadget driver is loaded and we are connected to a USB host,
> all transfers must be stopped before stopping the controller else
> we will not get a clean stop i.e. dwc3_gadget_run_stop() will take
> several seconds to complete and will return -ETIMEDOUT. Fix this.
>
> No need to stop the controller at dwc3_gadget_suspend() if
> dwc->softconnect is 0 as controller is already stopped.
>
> Handle error cases properly in dwc3_gadget_suspend().
We also fix the dwc3_gadget_resume() in this change. Either create a
separate change or note it in the $subject and commit message.
>
> Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Signed-off-by: Roger Quadros <rogerq@kernel.org>
Perhaps this needs a fixes tag? (Even though it can't be backported
cleanly without some modifications)
Also, please rebase your change to Greg's usb-next.
Thanks!
Thinh
@@ -2668,6 +2668,21 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
return dwc3_gadget_run_stop(dwc, false, false);
}
+static int dwc3_gadget_soft_connect(struct dwc3 *dwc)
+{
+ /*
+ * In the Synopsys DWC_usb31 1.90a programming guide section
+ * 4.1.9, it specifies that for a reconnect after a
+ * device-initiated disconnect requires a core soft reset
+ * (DCTL.CSftRst) before enabling the run/stop bit.
+ */
+ dwc3_core_soft_reset(dwc);
+
+ dwc3_event_buffers_setup(dwc);
+ __dwc3_gadget_start(dwc);
+ return dwc3_gadget_run_stop(dwc, true, false);
+}
+
static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
{
struct dwc3 *dwc = gadget_to_dwc(g);
@@ -2706,21 +2721,10 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
synchronize_irq(dwc->irq_gadget);
- if (!is_on) {
+ if (!is_on)
ret = dwc3_gadget_soft_disconnect(dwc);
- } else {
- /*
- * In the Synopsys DWC_usb31 1.90a programming guide section
- * 4.1.9, it specifies that for a reconnect after a
- * device-initiated disconnect requires a core soft reset
- * (DCTL.CSftRst) before enabling the run/stop bit.
- */
- dwc3_core_soft_reset(dwc);
-
- dwc3_event_buffers_setup(dwc);
- __dwc3_gadget_start(dwc);
- ret = dwc3_gadget_run_stop(dwc, true, false);
- }
+ else
+ ret = dwc3_gadget_soft_connect(dwc);
pm_runtime_put(dwc->dev);
@@ -4674,42 +4678,39 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
int dwc3_gadget_suspend(struct dwc3 *dwc)
{
unsigned long flags;
+ int ret;
- if (!dwc->gadget_driver)
+ if (!dwc->gadget_driver || !dwc->softconnect)
return 0;
- dwc3_gadget_run_stop(dwc, false, false);
+ ret = dwc3_gadget_soft_disconnect(dwc);
+ if (ret)
+ goto err;
spin_lock_irqsave(&dwc->lock, flags);
dwc3_disconnect_gadget(dwc);
- __dwc3_gadget_stop(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
return 0;
+
+err:
+ /*
+ * Attempt to reset the controller's state. Likely no
+ * communication can be established until the host
+ * performs a port reset.
+ */
+ if (dwc->softconnect)
+ dwc3_gadget_soft_connect(dwc);
+
+ return ret;
}
int dwc3_gadget_resume(struct dwc3 *dwc)
{
- int ret;
-
if (!dwc->gadget_driver || !dwc->softconnect)
return 0;
- ret = __dwc3_gadget_start(dwc);
- if (ret < 0)
- goto err0;
-
- ret = dwc3_gadget_run_stop(dwc, true, false);
- if (ret < 0)
- goto err1;
-
- return 0;
-
-err1:
- __dwc3_gadget_stop(dwc);
-
-err0:
- return ret;
+ return dwc3_gadget_soft_connect(dwc);
}
void dwc3_gadget_process_pending_events(struct dwc3 *dwc)