When a SuperSpeed device is plugged into non-SuperSpeed host or hub, it
will show up as a high speed or full speed device with a BCD USB version
number of 0x0201 or 0x210. It will also contain a SuperSpeed
Capabilities BOS descriptor.
If we see such a device, warn the user that they should plug their
device into a USB 3.0 hub or xHCI root port. Only warn the user if
there is at least one SuperSpeed roothub available.
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v3:
- Remove redundant speed checking.
- Warn about full or low speed devices that could run at SuperSpeed.
- Change description to remove false assumption about what BCD USB
shows up as under a UHCI/OHCI host.
drivers/usb/core/hub.c | 18 ++++++++++++++++++
1 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d4f0624..2553bcf 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1272,6 +1272,7 @@ static void hub_release(struct kref *kref)
}
static unsigned highspeed_hubs;
+static unsigned superspeed_hubs;
static void hub_disconnect(struct usb_interface *intf)
{
@@ -1295,6 +1296,8 @@ static void hub_disconnect(struct usb_interface *intf)
if (hub->hdev->speed == USB_SPEED_HIGH)
highspeed_hubs--;
+ if (hub->hdev->speed == USB_SPEED_SUPER)
+ superspeed_hubs--;
usb_free_urb(hub->urb);
kfree(hub->port_owners);
@@ -1372,6 +1375,8 @@ descriptor_error:
if (hdev->speed == USB_SPEED_HIGH)
highspeed_hubs++;
+ if (hub->hdev->speed == USB_SPEED_SUPER)
+ superspeed_hubs++;
if (hub_configure(hub, endpoint) >= 0)
return 0;
@@ -3230,6 +3235,15 @@ check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
kfree(qual);
}
+static void check_superspeed(struct usb_hub *hub, struct usb_device *udev,
+ int port1)
+{
+ if (udev->bos && udev->bos->ss_cap) {
+ dev_info(&udev->dev, "not running at top speed; "
+ "connect to a SuperSpeed port\n");
+ }
+}
+
static unsigned
hub_power_remaining (struct usb_hub *hub)
{
@@ -3449,6 +3463,10 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
&& udev->speed == USB_SPEED_FULL
&& highspeed_hubs != 0)
check_highspeed (hub, udev, port1);
+ if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201 &&
+ udev->speed < USB_SPEED_SUPER &&
+ superspeed_hubs != 0)
+ check_superspeed(hub, udev, port1);
/* Store the parent's children[] pointer. At this point
* udev becomes globally accessible, although presumably
--
1.7.9
--
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