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 585c3cb07da694d29cc825e282fc0efe4933b185..a5cc032ef77a8da22b86d9b29e4090e897d0bcc1 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -124,6 +124,10 @@ 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.
         */
@@ -4512,6 +4516,8 @@ 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) {
@@ -4710,7 +4716,6 @@ 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 fcd6ac0c667fe3ab5a200b80ac2f7535ee4ce779..6dc810bce295ab22dbb10b47755dddb421f96957 100644 (file)
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -202,6 +202,12 @@ static const struct usb_device_id usb_quirk_list[] = {
        { 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 9948c874e3f1e4e254ea666a3a7e623678edc26d..1d0043dc34e427403a1c82458249bed83e87d3a0 100644 (file)
--- 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 */