[PATCH 0/2] USB: propose a generic fix for PORT_SUSPEND set feature timeout

[PATCH 0/2] USB: propose a generic fix for PORT_SUSPEND set feature timeout

[chris.chiu]

From: Chris Chiu <chris.chiu@canonical.com>

For the Realtek Hub which fails to resume the port which has wakeup
enable descendants connected, trying to create a more generic and
better option to have the runtime suspend/resume work instead of
a reset-resume quirk.

Chris Chiu (2):
  USB: reset-resume the device when PORT_SUSPEND is set but timeout
  Revert "USB: Add reset-resume quirk for WD19's Realtek Hub"

 drivers/usb/core/hub.c    | 15 +++++++++++++++
 drivers/usb/core/quirks.c |  1 -
 2 files changed, 15 insertions(+), 1 deletion(-)

-- 
2.20.1

[PATCH 1/2] USB: reset-resume the device when PORT_SUSPEND is set but timeout

[chris.chiu]

From: Chris Chiu <chris.chiu@canonical.com>

On the Realtek hub of Dell Dock WD19, the port which has wakeup
enabled descendants will sometimes timeout when setting PORT_SUSPEND
feature. After checking the PORT_SUSPEND bit in wPortStatus, it is
already set. However, the hub will fail to activate because the
PORT_SUSPEND feature of that port is not cleared during resume. All
devices connecting via the port are lost after resume.

This commit force reset-resume the device connected to the timeout
but suspended port so that the hub will have chance to clear the
PORT_SUSPEND feature during resume.

Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
---
 drivers/usb/core/hub.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b2bc4b7c4289..18603949a8de 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3385,6 +3385,21 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		status = 0;
 	}
 	if (status) {
+		if (status == -ETIMEDOUT) {
+			u16 portstatus, portchange;
+
+			status = hub_port_status(hub, port1, &portstatus,
+					&portchange);
+
+			dev_dbg(&port_dev->dev,
+				"suspend timeout, status %04x\n", portstatus);
+
+			if (status == 0 && port_is_suspended(hub, portstatus)) {
+				udev->reset_resume = 1;
+				goto err_wakeup;
+			}
+		}
+
 		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
 
 		/* Try to enable USB3 LTM again */
-- 
2.20.1

Re: [PATCH 1/2] USB: reset-resume the device when PORT_SUSPEND is set but timeout

[Alan Stern]

On Fri, May 07, 2021 at 05:33:28PM +0800, chris.chiu@canonical.com wrote:
> From: Chris Chiu <chris.chiu@canonical.com>
> 
> On the Realtek hub of Dell Dock WD19, the port which has wakeup
> enabled descendants will sometimes timeout when setting PORT_SUSPEND
> feature. After checking the PORT_SUSPEND bit in wPortStatus, it is
> already set. However, the hub will fail to activate because the
> PORT_SUSPEND feature of that port is not cleared during resume. All
> devices connecting via the port are lost after resume.
> 
> This commit force reset-resume the device connected to the timeout
> but suspended port so that the hub will have chance to clear the
> PORT_SUSPEND feature during resume.
> 
> Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
> ---
>  drivers/usb/core/hub.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index b2bc4b7c4289..18603949a8de 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -3385,6 +3385,21 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
>  		status = 0;
>  	}
>  	if (status) {
> +		if (status == -ETIMEDOUT) {
> +			u16 portstatus, portchange;
> +
> +			status = hub_port_status(hub, port1, &portstatus,
> +					&portchange);

Don't reuse status like this.  There will be a problem if this line sets 
status to 0 but the port isn't actually suspended.  Use a different 
variable instead.

Alan Stern

> +
> +			dev_dbg(&port_dev->dev,
> +				"suspend timeout, status %04x\n", portstatus);
> +
> +			if (status == 0 && port_is_suspended(hub, portstatus)) {
> +				udev->reset_resume = 1;
> +				goto err_wakeup;
> +			}
> +		}
> +
>  		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
>  
>  		/* Try to enable USB3 LTM again */
> -- 
> 2.20.1
> 

[PATCH 2/2] Revert "USB: Add reset-resume quirk for WD19's Realtek Hub"

[chris.chiu]

From: Chris Chiu <chris.chiu@canonical.com>

This reverts commit ca91fd8c7643d93bfc18a6fec1a0d3972a46a18a. The
problematic hub should be taken care for each setting PORT_SUSPEND
feature timeout instead of reset-resume all the time.

Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
---
 drivers/usb/core/quirks.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 21e7522655ac..6114cf83bb44 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -406,7 +406,6 @@ static const struct usb_device_id usb_quirk_list[] = {
 
 	/* Realtek hub in Dell WD19 (Type-C) */
 	{ USB_DEVICE(0x0bda, 0x0487), .driver_info = USB_QUIRK_NO_LPM },
-	{ USB_DEVICE(0x0bda, 0x5487), .driver_info = USB_QUIRK_RESET_RESUME },
 
 	/* Generic RTL8153 based ethernet adapters */
 	{ USB_DEVICE(0x0bda, 0x8153), .driver_info = USB_QUIRK_NO_LPM },
-- 
2.20.1