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Message-ID: <20231017131851.8299-8-quic_kriskura@quicinc.com>
Date: Tue, 17 Oct 2023 18:48:51 +0530
From: Krishna Kurapati <quic_kriskura@...cinc.com>
To: Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Philipp Zabel <p.zabel@...gutronix.de>,
"Andy Gross" <agross@...nel.org>,
Bjorn Andersson <andersson@...nel.org>,
"Konrad Dybcio" <konrad.dybcio@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>, <quic_wcheng@...cinc.com>
CC: <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-msm@...r.kernel.org>, <devicetree@...r.kernel.org>,
<quic_ppratap@...cinc.com>, <quic_jackp@...cinc.com>,
Krishna Kurapati <quic_kriskura@...cinc.com>
Subject: [RFC 8/8] usb: dwc3: core: Skip set_mode notification if cable is disconnected
In device mode use cases, the following sequence of actions are observed:
1. Cable disconnect happens and clears qscratch HS_PHY_CTRL_REG properly
2. Disconnect event is generated and "connected" flag turns false.
3. Then the setmode notification from core goes to glue
4. Glue will set back the qscratch HS_PHY_CTRL_REG bits again.
At this point, since the cable is removed, setting qscratch bits shouldn't
affect anything. But it is observed that after setting this bits, the
controller generated Event-0x101 and Event-0x30601 (bus reset and suspend)
in order. In bus reset, we set back the "connected" flag and this blocks
suspend again.
So send set_mode call only if the cable is connected, else skip it.
Signed-off-by: Krishna Kurapati <quic_kriskura@...cinc.com>
---
drivers/usb/dwc3/core.c | 3 ++-
drivers/usb/dwc3/core.h | 2 ++
drivers/usb/dwc3/drd.c | 6 +++++-
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index b4d1d1c98dd5..6ef1e3558384 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -137,7 +137,8 @@ static void __dwc3_set_mode(struct work_struct *work)
if (!desired_dr_role)
goto out;
- dwc3_notify_set_mode(dwc, desired_dr_role);
+ if (dwc->cable_disconnected == false)
+ dwc3_notify_set_mode(dwc, desired_dr_role);
if (desired_dr_role == dwc->current_dr_role)
goto out;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 5ed7fd5eb776..1b79c407a798 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1365,6 +1365,8 @@ struct dwc3 {
void *glue_data;
const struct dwc3_glue_ops *glue_ops;
+
+ bool cable_disconnected;
};
#define INCRX_BURST_MODE 0
diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 947faeef0e4d..b3a87c40c4f1 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -446,6 +446,8 @@ static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
u32 mode;
+ dwc->cable_disconnected = false;
+
switch (role) {
case USB_ROLE_HOST:
mode = DWC3_GCTL_PRTCAP_HOST;
@@ -467,8 +469,10 @@ static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
* glue needs to know that we are disconnected. It must not notify
* the change of mode to default mode.
*/
- if (role == USB_ROLE_NONE)
+ if (role == USB_ROLE_NONE) {
+ dwc->cable_disconnected = true;
dwc3_notify_cable_disconnect(dwc);
+ }
dwc3_set_mode(dwc, mode);
return 0;
--
2.42.0
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