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From:   Fabrice Gasnier <fabrice.gasnier@st.com>
To:     <hminas@synopsys.com>
CC:     <gregkh@linuxfoundation.org>, <balbi@ti.com>,
        <johnyoun@synopsys.com>, <gregory.herrero@intel.com>,
        <Grigor.Tovmasyan@synopsys.com>, <amelie.delaunay@st.com>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>
Subject: [PATCH] usb: dwc2: only prevent new request when power_down is possible
Date:   Fri, 10 Apr 2020 16:31:54 +0200
Message-ID: <1586529114-25211-1-git-send-email-fabrice.gasnier@st.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When controller is suspended, registers mustn't be touched. This is not
the case when 'power_down' is set to none. In this case, power saving
routines are skipped.

This fixes a case where gadget driver (f_acm) gets opened (cat /dev/ttyGS0)
but the bus has been suspended by the host:
- configfs-gadget gadget: acm ttyGS0 can't notify serial state, -11

Fixes: 7ababa926c66 ("usb: dwc2: gadget: prevent new request submission during suspend")
Fixes: 88b02f2cb1e1 ("usb: dwc2: Add core state checking")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 drivers/usb/dwc2/gadget.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 92ed32e..45a8782 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -1375,7 +1375,8 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
 		req->zero, req->short_not_ok);
 
 	/* Prevent new request submission when controller is suspended */
-	if (hs->lx_state != DWC2_L0) {
+	if (hs->params.power_down != DWC2_POWER_DOWN_PARAM_NONE &&
+	    hs->lx_state != DWC2_L0) {
 		dev_dbg(hs->dev, "%s: submit request only in active state\n",
 			__func__);
 		return -EAGAIN;
-- 
2.7.4