USB: add quirk for devices with broken LPM
Some USB device / host controller combinations seem to have problems
with Link Power Management. For example, Steinar found that his xHCI
controller wouldn't handle bandwidth calculations correctly for two
video cards simultaneously when LPM was enabled, even though the bus
had plenty of bandwidth available.
This patch introduces a new quirk flag for devices that should remain
disabled for LPM, and creates quirk entries for Steinar's devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 585c3cb..a5cc032 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -124,6 +124,10 @@
int usb_device_supports_lpm(struct usb_device *udev)
{
+ /* Some devices have trouble with LPM */
+ if (udev->quirks & USB_QUIRK_NO_LPM)
+ return 0;
+
/* USB 2.1 (and greater) devices indicate LPM support through
* their USB 2.0 Extended Capabilities BOS descriptor.
*/
@@ -4512,6 +4516,8 @@
goto fail;
}
+ usb_detect_quirks(udev);
+
if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
retval = usb_get_bos_descriptor(udev);
if (!retval) {
@@ -4710,7 +4716,6 @@
if (status < 0)
goto loop;
- usb_detect_quirks(udev);
if (udev->quirks & USB_QUIRK_DELAY_INIT)
msleep(1000);
diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index fcd6ac0..6dc810b 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -202,6 +202,12 @@
{ USB_DEVICE(0x1a0a, 0x0200), .driver_info =
USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL },
+ /* Blackmagic Design Intensity Shuttle */
+ { USB_DEVICE(0x1edb, 0xbd3b), .driver_info = USB_QUIRK_NO_LPM },
+
+ /* Blackmagic Design UltraStudio SDI */
+ { USB_DEVICE(0x1edb, 0xbd4f), .driver_info = USB_QUIRK_NO_LPM },
+
{ } /* terminating entry must be last */
};
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index 9948c87..1d0043d 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -47,4 +47,7 @@
/* device generates spurious wakeup, ignore remote wakeup capability */
#define USB_QUIRK_IGNORE_REMOTE_WAKEUP BIT(9)
+/* device can't handle Link Power Management */
+#define USB_QUIRK_NO_LPM BIT(10)
+
#endif /* __LINUX_USB_QUIRKS_H */