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From:   Krishna Kurapati <quic_kriskura@quicinc.com>
To:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_wcheng@quicinc.com>,
        <quic_jackp@quicinc.com>, <quic_ugoswami@quicinc.com>,
        Krishna Kurapati <quic_kriskura@quicinc.com>
Subject: [PATCH] usb: dwc3: gadget: Propagate core init errors to UDC during pullup
Date:   Wed, 14 Jun 2023 19:19:22 +0530
Message-ID: <20230614134922.23516-1-quic_kriskura@quicinc.com>
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Precedence: bulk

In scenarios where pullup relies on resume (get sync) to initialize
the controller and set the run stop bit, then core_init is followed by
gadget_resume which will eventually set run stop bit.

But in cases where the core_init fails, the return value is not sent
back to udc appropriately. So according to UDC the controller has
started but in reality we never set the run stop bit.

On systems like Android, there are uevents sent to HAL depending on
whether the configfs_bind / configfs_disconnect were invoked. In the
above mentioned scnenario, if the core init fails, the run stop won't
be set and the cable plug-out won't result in generation of any
disconnect event and userspace would never get any uevent regarding
cable plug out and we never call pullup(0) again. Furthermore none of
the next Plug-In/Plug-Out's would be known to configfs.

Return back the appropriate result to UDC to let the userspace/
configfs know that the pullup failed so they can take appropriate
action.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
---
 drivers/usb/dwc3/gadget.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 578804dc29ca..27cb671e18e3 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2747,7 +2747,9 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 	ret = pm_runtime_get_sync(dwc->dev);
 	if (!ret || ret < 0) {
 		pm_runtime_put(dwc->dev);
-		return 0;
+		if (ret < 0)
+			pm_runtime_set_suspended(dwc->dev);
+		return ret;
 	}
 
 	if (dwc->pullups_connected == is_on) {
-- 
2.40.0