USB: add quirk for devices with broken LPM

commit ad87e03213b552a5c33d5e1e7a19a73768397010 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 882acb2a0b48e76bd6bc83636645b6ca5a435b8c..a1e577777a02c00c42a5e6da76ca52ba8833a857 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -128,6 +128,10 @@ struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
 
 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.
         */
@@ -4479,6 +4483,8 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
                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) {
@@ -4674,7 +4680,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
                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 2b978ad9d9effced140e42dcb60c15a02a5639d3..0e8e656a045f6b90766729f42fbe3cac8440b1b0 100644 (file)
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -188,6 +188,12 @@ static const struct usb_device_id usb_quirk_list[] = {
        /* USB3503 */
        { USB_DEVICE(0x0424, 0x3503), .driver_info = USB_QUIRK_RESET_RESUME },
 
+       /* 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 4a185a0f624262c970141a007b1e8296814ba199..8f4f2214652f6c95b4d0af42e6ff83db9b01209b 100644 (file)
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -47,4 +47,7 @@
 /* device can't handle device_qualifier descriptor requests */
 #define USB_QUIRK_DEVICE_QUALIFIER     0x00000100
 
+/* device can't handle Link Power Management */
+#define USB_QUIRK_NO_LPM                       BIT(10)
+
 #endif /* __LINUX_USB_QUIRKS_H */