Re: [PATCH v2] usb: common: usb-conn-gpio: Set last role to unknown before initial detection

From: AngeloGioacchino Del Regno
Date: Thu May 25 2023 - 04:08:02 EST


Il 24/05/23 15:50, Prashanth K ha scritto:
Currently if we bootup a device without cable connected, then
usb-conn-gpio won't call set_role() since last_role is same as
current role. This happens because during probe last_role gets
initialized to zero.

To avoid this, added a new constant in enum usb_role, last_role
is set to USB_ROLE_UNKNOWN before performing initial detection.

Fixes: 4602f3bff266 ("usb: common: add USB GPIO based connection detection driver")
Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>

There's an issue with drivers/usb/cdns3/core.c as pointed out by the
test robot; the solution is to handle `default` in the switch, I'd say
that it would be safe to handle it as

default:
break;

after solving that:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>

---
v2: Added USB_ROLE_UNKNWON to enum usb_role

drivers/usb/common/usb-conn-gpio.c | 3 +++
include/linux/usb/role.h | 1 +
2 files changed, 4 insertions(+)

diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c
index e20874c..30bdb81 100644
--- a/drivers/usb/common/usb-conn-gpio.c
+++ b/drivers/usb/common/usb-conn-gpio.c
@@ -257,6 +257,9 @@ static int usb_conn_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, info);
device_set_wakeup_capable(&pdev->dev, true);
+ /* Set last role to unknown before performing the initial detection */
+ info->last_role = USB_ROLE_UNKNOWN;
+
/* Perform initial detection */
usb_conn_queue_dwork(info, 0);
diff --git a/include/linux/usb/role.h b/include/linux/usb/role.h
index b5deafd..221d462 100644
--- a/include/linux/usb/role.h
+++ b/include/linux/usb/role.h
@@ -8,6 +8,7 @@
struct usb_role_switch;
enum usb_role {
+ USB_ROLE_UNKNOWN = -1,
USB_ROLE_NONE,
USB_ROLE_HOST,
USB_ROLE_DEVICE,