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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Felipe Balbi <balbi@kernel.org>
Subject: [PATCH 5.4 75/85] usb: dwc3: ep0: Fix delay status handling
Date:   Mon,  9 Nov 2020 13:56:12 +0100
Message-Id: <20201109125026.180567725@linuxfoundation.org>
In-Reply-To: <20201109125022.614792961@linuxfoundation.org>
References: <20201109125022.614792961@linuxfoundation.org>
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From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

commit fa27e2f6c5e674f3f1225f9ca7a7821faaf393bb upstream.

If we want to send a control status on our own time (through
delayed_status), make sure to handle a case where we may queue the
delayed status before the host requesting for it (when XferNotReady
is generated). Otherwise, the driver won't send anything because it's
not EP0_STATUS_PHASE yet. To resolve this, regardless whether
dwc->ep0state is EP0_STATUS_PHASE, make sure to clear the
dwc->delayed_status flag if dwc3_ep0_send_delayed_status() is called.
The control status can be sent when the host requests it later.

Cc: <stable@vger.kernel.org>
Fixes: d97c78a1908e ("usb: dwc3: gadget: END_TRANSFER before CLEAR_STALL command")
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/dwc3/ep0.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -1058,10 +1058,11 @@ void dwc3_ep0_send_delayed_status(struct
 {
 	unsigned int direction = !dwc->ep0_expect_in;
 
+	dwc->delayed_status = false;
+
 	if (dwc->ep0state != EP0_STATUS_PHASE)
 		return;
 
-	dwc->delayed_status = false;
 	__dwc3_ep0_do_control_status(dwc, dwc->eps[direction]);
 }