If a broken accessory connected to a USB host, usbcore might
keep doing enumeration retries and it will take a long time to
cause system unstable.
This patch provides a quirk to specific USB ports of the hub to
stop USB enumeration if needed.
Signed-off-by: Ray Chi <raychi@xxxxxxxxxx>
---
Changes since v1:
- remove usb_hub_set_port_power()
- add a variable ignore_connect into struct port_dev
- modify hub_port_stop_enumerate() and set ignore_connect in
this function
- avoid calling hub_port_connect_change() in port_event()
---
drivers/usb/core/hub.c | 40 ++++++++++++++++++++++++++++++++++++++++
drivers/usb/core/hub.h | 2 ++
include/linux/usb.h | 3 +++
3 files changed, 45 insertions(+)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2633acde7ac1..7f34ee8bb81e 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3081,6 +3081,30 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
return status;
}
+/* Stop enumerate if the port met errors and quirk is set */
+static bool hub_port_stop_enumerate(struct usb_hub *hub, int port1, int retries)
+{
+ struct usb_port *port_dev = hub->ports[port1 - 1];
+
+ if (port_dev->quirks & USB_PORT_QUIRK_STOP_ENUM) {
+ if (port_dev->ignore_connect)
+ return true;
+
+ if (retries < (PORT_INIT_TRIES - 1) / 2)
+ return false;
+
+ /*
+ * Some USB hosts can't take a long time to keep doing enumeration
+ * retry. After doing half of the retries, we would turn off the port
+ * power to stop enumeration if the quirk is set.
+ */
+ port_dev->ignore_connect = true;
+ } else
+ port_dev->ignore_connect = false;
+
+ return port_dev->ignore_connect;
+}
+
/* Check if a port is power on */
int usb_port_is_power_on(struct usb_hub *hub, unsigned int portstatus)
{
@@ -4855,6 +4879,11 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
buf->bMaxPacketSize0;
kfree(buf);
+ if (r < 0 && (port_dev->quirks & USB_PORT_QUIRK_STOP_ENUM)) {
+ retval = r;
+ goto fail;
+ }
+
retval = hub_port_reset(hub, port1, udev, delay, false);
if (retval < 0) /* error or disconnect */
goto fail;
@@ -5387,6 +5416,9 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
if ((status == -ENOTCONN) || (status == -ENOTSUPP))
break;
+ if (hub_port_stop_enumerate(hub, port1, i))
+ break;
+
/* When halfway through our retry count, power-cycle the port */
if (i == (PORT_INIT_TRIES - 1) / 2) {
dev_info(&port_dev->dev, "attempt power cycle\n");
@@ -5550,6 +5582,9 @@ static void port_event(struct usb_hub *hub, int port1)
if (usb_hub_port_status(hub, port1, &portstatus, &portchange) < 0)
return;
+ if (hub_port_stop_enumerate(hub, port1, 0))
+ return;
+
if (portchange & USB_PORT_STAT_C_CONNECTION) {
usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
connect_change = 1;
@@ -5934,6 +5969,9 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
ret = hub_port_init(parent_hub, udev, port1, i);
if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
break;
+
+ if (hub_port_stop_enumerate(parent_hub, port1, i))
+ goto stop_enumerate;
}
mutex_unlock(hcd->address0_mutex);
@@ -6022,6 +6060,8 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
udev->bos = bos;
return 0;
+stop_enumerate:
+ mutex_unlock(hcd->address0_mutex);
re_enumerate:
usb_release_bos_descriptor(udev);
udev->bos = bos;
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index b2925856b4cb..f0aa718f4c7f 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -90,6 +90,7 @@ struct usb_hub {
* @is_superspeed cache super-speed status
* @usb3_lpm_u1_permit: whether USB3 U1 LPM is permitted.
* @usb3_lpm_u2_permit: whether USB3 U2 LPM is permitted.
+ * @ignore_connect: ignore the connection or not
*/
struct usb_port {
struct usb_device *child;
@@ -103,6 +104,7 @@ struct usb_port {
u32 over_current_count;
u8 portnum;
u32 quirks;
+ bool ignore_connect;
unsigned int is_superspeed:1;
unsigned int usb3_lpm_u1_permit:1;
unsigned int usb3_lpm_u2_permit:1;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index f7a9914fc97f..fc0fef58c706 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -490,6 +490,9 @@ enum usb_port_connect_type {
/* Decrease TRSTRCY to 10ms during device enumeration. */
#define USB_PORT_QUIRK_FAST_ENUM BIT(1)
+/* Stop the enumeration for the given port if there are too many failures*/
+#define USB_PORT_QUIRK_STOP_ENUM BIT(2)
+
/*
* USB 2.0 Link Power Management (LPM) parameters.
*/
--
2.37.2.789.g6183377224-goog
