From: Shuah Khan <skhan@linuxfoundation.org>
To: Michael Broadfoot <msbroadf@gmail.com>,
valentina.manea.m@gmail.com, shuah@kernel.org,
gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org,
Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH v2] vhci_hcd: USB port can get stuck in the disabled state
Date: Wed, 21 Jul 2021 19:26:02 -0600 [thread overview]
Message-ID: <7b02cb66-d672-ae95-01ea-c6015725e1ac@linuxfoundation.org> (raw)
In-Reply-To: <20210721235526.10588-1-msbroadf@gmail.com>
On 7/21/21 5:55 PM, Michael Broadfoot wrote:
> When a remote usb device is attached to the local Virtual USB
> Host Controller Root Hub port, the bound device driver may send a
> port reset command. For example to initialize firmware (eg. btusb does this).
> This port reset command can be sent at any time, however the VHCI hcd
> root hub is only expecting reset to occur before the device receives
> SET_ADDRESS. The USB port should always be enabled after a reset
> (because the port is virtual and there is no possibility of hardware errors)
>
>
>
> Signed-off-by: Michael Broadfoot <msbroadf@gmail.com>
> ---
> drivers/usb/usbip/vhci_hcd.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
> index 4ba6bcdaa8e9..d3cda1b2c15a 100644
> --- a/drivers/usb/usbip/vhci_hcd.c
> +++ b/drivers/usb/usbip/vhci_hcd.c
> @@ -455,15 +455,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> vhci_hcd->port_status[rhport] &= ~(1 << USB_PORT_FEAT_RESET);
> vhci_hcd->re_timeout = 0;
>
> - if (vhci_hcd->vdev[rhport].ud.status ==
> - VDEV_ST_NOTASSIGNED) {
> - usbip_dbg_vhci_rh(
> - " enable rhport %d (status %u)\n",
> - rhport,
> - vhci_hcd->vdev[rhport].ud.status);
> - vhci_hcd->port_status[rhport] |=
> - USB_PORT_STAT_ENABLE;
> - }
VDEV_ST_NOTASSIGNED status indicates that the vdev is in use without
address assigned - in other words port is initializing.
This is part of the attach request handling when user requests to
attach to a remote device. attach_store() will change the status
to VDEV_ST_NOTASSIGNED and then initiate port_connect sequence.
We don't want to touch the vdev when it is in other states.
> + usbip_dbg_vhci_rh(" enable rhport %d (status %u)\n",
> + rhport,
> + vhci_hcd->vdev[rhport].ud.status);
> + vhci_hcd->port_status[rhport] |= USB_PORT_STAT_ENABLE;
>
> if (hcd->speed < HCD_USB3) {
> switch (vhci_hcd->vdev[rhport].speed) {
>
How did you find this problem? Does the port get into stuck state
while attaching to a remote usbip device on the host?
thanks,
-- Shuah
next prev parent reply other threads:[~2021-07-22 1:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 23:55 [PATCH v2] vhci_hcd: USB port can get stuck in the disabled state Michael Broadfoot
2021-07-22 1:26 ` Shuah Khan [this message]
[not found] ` <CALdjXpA4_eXen6RjhsEBYt8CQs-2gzwYs9h9q0Z2LKZ=rXVp+Q@mail.gmail.com>
2021-07-22 6:19 ` Michael
2021-07-23 16:29 ` Shuah Khan
2021-07-23 23:53 ` Michael
2021-07-23 23:58 ` Michael
2021-07-30 22:52 ` Shuah Khan
2021-07-30 23:52 ` Michael
2021-08-02 23:14 ` Shuah Khan
2021-08-03 1:00 ` Michael
2021-08-10 17:46 ` Shuah Khan
2021-08-11 2:30 ` Michael
2021-08-19 22:57 ` Shuah Khan
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