[PATCH 0/4] Fix DWC2 USB role switch support

[PATCH 0/4] Fix DWC2 USB role switch support

[Amelie Delaunay]

This patchset adds missing documentation for usb-role-switch support in DWC2
bindings. It also fixes build issue when config is DWC2_HOST only, 
sleeping while atomic issue and missing usb-role-switch unregistration in probe
error path.

Amelie Delaunay (4):
  dt-bindings: usb: dwc2: add optional usb-role-switch property
  usb: dwc2: fix build issue when config is USB_DWC2_HOST only
  usb: dwc2: drd: fix sleeping while spinlock atomic context
  usb: dwc2: fix error path with missing dwc2_drd_exit

 .../devicetree/bindings/usb/dwc2.yaml         |  4 +++
 drivers/usb/dwc2/core.h                       |  1 +
 drivers/usb/dwc2/drd.c                        | 30 +++++++------------
 drivers/usb/dwc2/platform.c                   |  2 ++
 4 files changed, 17 insertions(+), 20 deletions(-)

-- 
2.17.1

[PATCH 1/4] dt-bindings: usb: dwc2: add optional usb-role-switch property

[Amelie Delaunay]

This patch documents the usb-role-switch property in dwc2 bindings, now
that usb-role-switch support is available in dwc2 driver.

Fixes: bc0f0d4a5853 ("usb: dwc2: override PHY input signals with usb role switch support")
Reported-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
---
 Documentation/devicetree/bindings/usb/dwc2.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc2.yaml b/Documentation/devicetree/bindings/usb/dwc2.yaml
index 9352a8ef60a6..7b226eeffe82 100644
--- a/Documentation/devicetree/bindings/usb/dwc2.yaml
+++ b/Documentation/devicetree/bindings/usb/dwc2.yaml
@@ -100,6 +100,10 @@ properties:
   dr_mode:
     enum: [host, peripheral, otg]
 
+  usb-role-switch:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: Support role switch.
+
   g-rx-fifo-size:
     $ref: /schemas/types.yaml#/definitions/uint32
     description: size of rx fifo size in gadget mode.
-- 
2.17.1

[PATCH 2/4] usb: dwc2: fix build issue when config is USB_DWC2_HOST only

[Amelie Delaunay]

This patch add missing definition of dwc2_hsotg_core_disconnect and
check configuration before using hsotg->test_mode, to fix build issue when
config USB_DWC2_PERIPHERAL or USB_DWC2_DUAL_ROLE are not set.

Fixes: bc0f0d4a5853 ("usb: dwc2: override PHY input signals with usb role switch support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
---
 drivers/usb/dwc2/core.h | 1 +
 drivers/usb/dwc2/drd.c  | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 33e790ccefb3..7161344c6522 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -1425,6 +1425,7 @@ static inline int dwc2_gadget_init(struct dwc2_hsotg *hsotg)
 { return 0; }
 static inline void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *dwc2,
 						     bool reset) {}
+static inline void dwc2_hsotg_core_disconnect(struct dwc2_hsotg *hsotg) {}
 static inline void dwc2_hsotg_core_connect(struct dwc2_hsotg *hsotg) {}
 static inline void dwc2_hsotg_disconnect(struct dwc2_hsotg *dwc2) {}
 static inline int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg,
diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
index 032efffa37ab..5099841b1417 100644
--- a/drivers/usb/dwc2/drd.c
+++ b/drivers/usb/dwc2/drd.c
@@ -76,11 +76,14 @@ static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
 	    (role == USB_ROLE_HOST && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL))
 		return -EINVAL;
 
+#if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || \
+	IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
 	/* Skip session if core is in test mode */
 	if (role == USB_ROLE_NONE && hsotg->test_mode) {
 		dev_dbg(hsotg->dev, "Core is in test mode\n");
 		return -EBUSY;
 	}
+#endif
 
 	spin_lock_irqsave(&hsotg->lock, flags);
 
-- 
2.17.1

[PATCH 3/4] usb: dwc2: drd: fix sleeping while spinlock atomic context

[Amelie Delaunay]

If GINTSTS.CURMODE is not yet reflecting the expecting mode after calling
dwc2_force_mode, we enter in the dwc2_wait_for_mode function while under
spinlock atomic context.
To avoid this situation, move the call to dwc2_force_mode after the
spinlock atomic context.

Fixes: bc0f0d4a5853 ("usb: dwc2: override PHY input signals with usb role switch support")
Reported-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
---
 drivers/usb/dwc2/drd.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
index 5099841b1417..2d4176f5788e 100644
--- a/drivers/usb/dwc2/drd.c
+++ b/drivers/usb/dwc2/drd.c
@@ -70,6 +70,7 @@ static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
 {
 	struct dwc2_hsotg *hsotg = usb_role_switch_get_drvdata(sw);
 	unsigned long flags;
+	int already = 0;
 
 	/* Skip session not in line with dr_mode */
 	if ((role == USB_ROLE_DEVICE && hsotg->dr_mode == USB_DR_MODE_HOST) ||
@@ -88,26 +89,9 @@ static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
 	spin_lock_irqsave(&hsotg->lock, flags);
 
 	if (role == USB_ROLE_HOST) {
-		if (dwc2_ovr_avalid(hsotg, true))
-			goto unlock;
-
-		if (hsotg->dr_mode == USB_DR_MODE_OTG)
-			/*
-			 * This will raise a Connector ID Status Change
-			 * Interrupt - connID A
-			 */
-			dwc2_force_mode(hsotg, true);
+		already = dwc2_ovr_avalid(hsotg, true);
 	} else if (role == USB_ROLE_DEVICE) {
-		if (dwc2_ovr_bvalid(hsotg, true))
-			goto unlock;
-
-		if (hsotg->dr_mode == USB_DR_MODE_OTG)
-			/*
-			 * This will raise a Connector ID Status Change
-			 * Interrupt - connID B
-			 */
-			dwc2_force_mode(hsotg, false);
-
+		already = dwc2_ovr_bvalid(hsotg, true);
 		/* This clear DCTL.SFTDISCON bit */
 		dwc2_hsotg_core_connect(hsotg);
 	} else {
@@ -120,9 +104,12 @@ static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
 		}
 	}
 
-unlock:
 	spin_unlock_irqrestore(&hsotg->lock, flags);
 
+	if (!already && hsotg->dr_mode == USB_DR_MODE_OTG)
+		/* This will raise a Connector ID Status Change Interrupt */
+		dwc2_force_mode(hsotg, role == USB_ROLE_HOST);
+
 	dev_dbg(hsotg->dev, "%s-session valid\n",
 		role == USB_ROLE_NONE ? "No" :
 		role == USB_ROLE_HOST ? "A" : "B");
-- 
2.17.1

[PATCH 4/4] usb: dwc2: fix error path with missing dwc2_drd_exit

[Amelie Delaunay]

In case of failure, role switch has to be unregistered. It is done by
dwc2_drd_exit.

Fixes: bc0f0d4a5853 ("usb: dwc2: override PHY input signals with usb role switch support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
---
 drivers/usb/dwc2/platform.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 68b56b43a45e..f4a0371c3e89 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -600,6 +600,8 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	return 0;
 
 error_init:
+	dwc2_drd_exit(hsotg);
+
 	if (hsotg->params.activate_stm_id_vb_detection)
 		regulator_disable(hsotg->usb33d);
 error:
-- 
2.17.1

Re: [PATCH 0/4] Fix DWC2 USB role switch support

[Amelie DELAUNAY]

On 7/24/20 2:37 PM, Amelie DELAUNAY wrote:
> This patchset adds missing documentation for usb-role-switch support in DWC2
> bindings. It also fixes build issue when config is DWC2_HOST only,
> sleeping while atomic issue and missing usb-role-switch unregistration 
> in probe
> error path.
> 
> Amelie Delaunay (4):
>    dt-bindings: usb: dwc2: add optional usb-role-switch property
>    usb: dwc2: fix build issue when config is USB_DWC2_HOST only
>    usb: dwc2: drd: fix sleeping while spinlock atomic context
>    usb: dwc2: fix error path with missing dwc2_drd_exit
> 
>   .../devicetree/bindings/usb/dwc2.yaml         |  4 +++
>   drivers/usb/dwc2/core.h                       |  1 +
>   drivers/usb/dwc2/drd.c                        | 30 +++++++------------
>   drivers/usb/dwc2/platform.c                   |  2 ++
>   4 files changed, 17 insertions(+), 20 deletions(-)
> 
> -- 
> 2.17.1
> 

Patchset dropped.

Regards,
Amelie