* [PATCH] usb: core: Avoid doing warm reset on disconnect event
@ 2021-11-26 3:26 Kai-Heng Feng
2021-11-26 6:53 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Kai-Heng Feng @ 2021-11-26 3:26 UTC (permalink / raw)
To: gregkh
Cc: stern, mathias.nyman, Kai-Heng Feng, Thinh Nguyen, Bixuan Cui,
Andrew Lunn, Chris Chiu, Rajat Jain, linux-usb, linux-kernel
Unplugging USB device may cause an incorrect warm reset loop:
[ 143.039019] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x4202c0
[ 143.039025] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
[ 143.039051] hub 2-0:1.0: state 7 ports 10 chg 0000 evt 0008
[ 143.039058] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x4202c0, return 0x4102c0
[ 143.039092] xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x4002c0
[ 143.039096] usb usb2-port3: link state change
[ 143.039099] xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0
[ 143.039101] usb usb2-port3: do warm reset
[ 143.096736] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0
[ 143.096751] usb usb2-port3: not warm reset yet, waiting 50ms
[ 143.131500] xhci_hcd 0000:00:14.0: Can't queue urb, port error, link inactive
[ 143.138260] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x2802a0
[ 143.138263] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
[ 143.160756] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2802a0, return 0x3002a0
[ 143.160798] usb usb2-port3: not warm reset yet, waiting 200ms
The warm reset is due to its PLS is in eSS.Inactive state. However, USB
3.2 spec table 10-13 mentions "Ports can be disabled by either a fault
condition (disconnect event or other fault condition)", xHCI 1.2 spec
table 5-27 also states that "This flag shall automatically be cleared to
‘0’ by a disconnect event or other fault condition." on PED.
So use CSC = 0 and PED = 0 as indication that device is disconnecting to
avoid doing warm reset.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
drivers/usb/core/hub.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 86658a81d2844..abd5a83d194b0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5530,6 +5530,7 @@ static void port_event(struct usb_hub *hub, int port1)
__must_hold(&port_dev->status_lock)
{
int connect_change;
+ int disconnect = 0;
struct usb_port *port_dev = hub->ports[port1 - 1];
struct usb_device *udev = port_dev->child;
struct usb_device *hdev = hub->hdev;
@@ -5545,6 +5546,9 @@ static void port_event(struct usb_hub *hub, int port1)
if (portchange & USB_PORT_STAT_C_CONNECTION) {
usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
connect_change = 1;
+ if (!(portstatus & USB_PORT_STAT_CONNECTION) &&
+ !(portstatus & USB_PORT_STAT_ENABLE))
+ disconnect = 1;
}
if (portchange & USB_PORT_STAT_C_ENABLE) {
@@ -5613,7 +5617,7 @@ static void port_event(struct usb_hub *hub, int port1)
* Warm reset a USB3 protocol port if it's in
* SS.Inactive state.
*/
- if (hub_port_warm_reset_required(hub, port1, portstatus)) {
+ if (hub_port_warm_reset_required(hub, port1, portstatus) && !disconnect) {
dev_dbg(&port_dev->dev, "do warm reset\n");
if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
|| udev->state == USB_STATE_NOTATTACHED) {
--
2.32.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] usb: core: Avoid doing warm reset on disconnect event
2021-11-26 3:26 [PATCH] usb: core: Avoid doing warm reset on disconnect event Kai-Heng Feng
@ 2021-11-26 6:53 ` Greg KH
2021-11-26 11:49 ` Kai-Heng Feng
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2021-11-26 6:53 UTC (permalink / raw)
To: Kai-Heng Feng
Cc: stern, mathias.nyman, Thinh Nguyen, Bixuan Cui, Andrew Lunn,
Chris Chiu, Rajat Jain, linux-usb, linux-kernel
On Fri, Nov 26, 2021 at 11:26:21AM +0800, Kai-Heng Feng wrote:
> Unplugging USB device may cause an incorrect warm reset loop:
> [ 143.039019] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x4202c0
> [ 143.039025] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
> [ 143.039051] hub 2-0:1.0: state 7 ports 10 chg 0000 evt 0008
> [ 143.039058] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x4202c0, return 0x4102c0
> [ 143.039092] xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x4002c0
> [ 143.039096] usb usb2-port3: link state change
> [ 143.039099] xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0
> [ 143.039101] usb usb2-port3: do warm reset
> [ 143.096736] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0
> [ 143.096751] usb usb2-port3: not warm reset yet, waiting 50ms
> [ 143.131500] xhci_hcd 0000:00:14.0: Can't queue urb, port error, link inactive
> [ 143.138260] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x2802a0
> [ 143.138263] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
> [ 143.160756] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2802a0, return 0x3002a0
> [ 143.160798] usb usb2-port3: not warm reset yet, waiting 200ms
>
> The warm reset is due to its PLS is in eSS.Inactive state. However, USB
> 3.2 spec table 10-13 mentions "Ports can be disabled by either a fault
> condition (disconnect event or other fault condition)", xHCI 1.2 spec
> table 5-27 also states that "This flag shall automatically be cleared to
> ‘0’ by a disconnect event or other fault condition." on PED.
>
> So use CSC = 0 and PED = 0 as indication that device is disconnecting to
> avoid doing warm reset.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> drivers/usb/core/hub.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 86658a81d2844..abd5a83d194b0 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -5530,6 +5530,7 @@ static void port_event(struct usb_hub *hub, int port1)
> __must_hold(&port_dev->status_lock)
> {
> int connect_change;
> + int disconnect = 0;
bool?
> struct usb_port *port_dev = hub->ports[port1 - 1];
> struct usb_device *udev = port_dev->child;
> struct usb_device *hdev = hub->hdev;
> @@ -5545,6 +5546,9 @@ static void port_event(struct usb_hub *hub, int port1)
> if (portchange & USB_PORT_STAT_C_CONNECTION) {
> usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
> connect_change = 1;
> + if (!(portstatus & USB_PORT_STAT_CONNECTION) &&
> + !(portstatus & USB_PORT_STAT_ENABLE))
> + disconnect = 1;
> }
>
> if (portchange & USB_PORT_STAT_C_ENABLE) {
> @@ -5613,7 +5617,7 @@ static void port_event(struct usb_hub *hub, int port1)
> * Warm reset a USB3 protocol port if it's in
> * SS.Inactive state.
> */
> - if (hub_port_warm_reset_required(hub, port1, portstatus)) {
> + if (hub_port_warm_reset_required(hub, port1, portstatus) && !disconnect) {
Why is this problem just showing up now? What commit caused this
regression?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] usb: core: Avoid doing warm reset on disconnect event
2021-11-26 6:53 ` Greg KH
@ 2021-11-26 11:49 ` Kai-Heng Feng
0 siblings, 0 replies; 3+ messages in thread
From: Kai-Heng Feng @ 2021-11-26 11:49 UTC (permalink / raw)
To: Greg KH
Cc: stern, mathias.nyman, Thinh Nguyen, Bixuan Cui, Andrew Lunn,
Chris Chiu, Rajat Jain, linux-usb, linux-kernel
On Fri, Nov 26, 2021 at 2:53 PM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Fri, Nov 26, 2021 at 11:26:21AM +0800, Kai-Heng Feng wrote:
> > Unplugging USB device may cause an incorrect warm reset loop:
> > [ 143.039019] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x4202c0
> > [ 143.039025] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
> > [ 143.039051] hub 2-0:1.0: state 7 ports 10 chg 0000 evt 0008
> > [ 143.039058] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x4202c0, return 0x4102c0
> > [ 143.039092] xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x4002c0
> > [ 143.039096] usb usb2-port3: link state change
> > [ 143.039099] xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0
> > [ 143.039101] usb usb2-port3: do warm reset
> > [ 143.096736] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0
> > [ 143.096751] usb usb2-port3: not warm reset yet, waiting 50ms
> > [ 143.131500] xhci_hcd 0000:00:14.0: Can't queue urb, port error, link inactive
> > [ 143.138260] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x2802a0
> > [ 143.138263] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling.
> > [ 143.160756] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2802a0, return 0x3002a0
> > [ 143.160798] usb usb2-port3: not warm reset yet, waiting 200ms
> >
> > The warm reset is due to its PLS is in eSS.Inactive state. However, USB
> > 3.2 spec table 10-13 mentions "Ports can be disabled by either a fault
> > condition (disconnect event or other fault condition)", xHCI 1.2 spec
> > table 5-27 also states that "This flag shall automatically be cleared to
> > ‘0’ by a disconnect event or other fault condition." on PED.
> >
> > So use CSC = 0 and PED = 0 as indication that device is disconnecting to
> > avoid doing warm reset.
> >
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
> > drivers/usb/core/hub.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index 86658a81d2844..abd5a83d194b0 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -5530,6 +5530,7 @@ static void port_event(struct usb_hub *hub, int port1)
> > __must_hold(&port_dev->status_lock)
> > {
> > int connect_change;
> > + int disconnect = 0;
>
> bool?
Will change.
>
> > struct usb_port *port_dev = hub->ports[port1 - 1];
> > struct usb_device *udev = port_dev->child;
> > struct usb_device *hdev = hub->hdev;
> > @@ -5545,6 +5546,9 @@ static void port_event(struct usb_hub *hub, int port1)
> > if (portchange & USB_PORT_STAT_C_CONNECTION) {
> > usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
> > connect_change = 1;
> > + if (!(portstatus & USB_PORT_STAT_CONNECTION) &&
> > + !(portstatus & USB_PORT_STAT_ENABLE))
> > + disconnect = 1;
> > }
> >
> > if (portchange & USB_PORT_STAT_C_ENABLE) {
> > @@ -5613,7 +5617,7 @@ static void port_event(struct usb_hub *hub, int port1)
> > * Warm reset a USB3 protocol port if it's in
> > * SS.Inactive state.
> > */
> > - if (hub_port_warm_reset_required(hub, port1, portstatus)) {
> > + if (hub_port_warm_reset_required(hub, port1, portstatus) && !disconnect) {
>
> Why is this problem just showing up now? What commit caused this
> regression?
It's not a regression, the issue happens on all kernels I tried.
port_event() stays unchanged for a while.
Kai-Heng
>
> thanks,
>
> greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-11-26 11:51 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-11-26 3:26 [PATCH] usb: core: Avoid doing warm reset on disconnect event Kai-Heng Feng
2021-11-26 6:53 ` Greg KH
2021-11-26 11:49 ` Kai-Heng Feng
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox