usb: dwc3: gadget: Improve dwc3_gadget_suspend() and dwc3_gadget_resume()

commit c8540870af4ce6ddeb27a7bb5498b75fb29b643c upstream.

Prevent -ETIMEDOUT error on .suspend().
e.g. 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.

Handle error cases properly in dwc3_gadget_suspend().
Simplify dwc3_gadget_resume() by using the introduced helper function.

Fixes: f14ba2862d0a ("usb: dwc3: gadget: fix gadget suspend/resume")
Cc: stable@vger.kernel.org
Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20230503110048.30617-1-rogerq@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index daa7673833557082f01021af1fc47a355997bcb9..d12cb8f0d1f484879abb0b180ad1cc484f0814ef 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2587,6 +2587,21 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
        return ret;
 }
 
+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);
+}
+
 static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 {
        struct dwc3             *dwc = gadget_to_dwc(g);
@@ -2625,21 +2640,10 @@ 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);
-       }
+       else
+               ret = dwc3_gadget_soft_connect(dwc);
 
        pm_runtime_put(dwc->dev);
 
@@ -4555,42 +4559,39 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 int dwc3_gadget_suspend(struct dwc3 *dwc)
 {
        unsigned long flags;
+       int ret;
 
        if (!dwc->gadget_driver)
                return 0;
 
-       dwc3_gadget_run_stop(dwc, 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);
-       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)