Re: [PATCH v2 3/3] USB: Disable LPM on WD19's Realtek Hub

From: Alan Stern
Date: Fri Jan 10 2020 - 10:40:31 EST


On Fri, 10 Jan 2020, Kai-Heng Feng wrote:

> Realtek Hub (0bda:0x0487) used in Dell Dock WD19 sometimes drops off the
> bus when bringing underlying ports from U3 to U0.
>
> Disabling LPM on the hub during setting link state is not enough, so
> let's disable LPM completely for this hub.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
> drivers/usb/core/quirks.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
> index 6b6413073584..2fb7c1602280 100644
> --- a/drivers/usb/core/quirks.c
> +++ b/drivers/usb/core/quirks.c
> @@ -371,6 +371,9 @@ static const struct usb_device_id usb_quirk_list[] = {
> { USB_DEVICE(0x0b05, 0x17e0), .driver_info =
> USB_QUIRK_IGNORE_REMOTE_WAKEUP },
>
> + /* Realtek hub in Dell WD19 (Type-C) */
> + { USB_DEVICE(0x0bda, 0x0487), .driver_info = USB_QUIRK_NO_LPM },
> +
> /* Action Semiconductor flash disk */
> { USB_DEVICE(0x10d6, 0x2200), .driver_info =
> USB_QUIRK_STRING_FETCH_255 },
>

This is a very partial patch. There were four hunks in the original
version but there's only one hunk in V2.

Alan Stern