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 <[email protected]> Reported-by: Steinar H. Gunderson <[email protected]> --- [as1786] drivers/usb/core/hub.c | 7 ++++++- drivers/usb/core/quirks.c | 6 ++++++ include/linux/usb/quirks.h | 3 +++ 3 files changed, 15 insertions(+), 1 deletion(-) Index: usb-4.3/include/linux/usb/quirks.h =================================================================== --- usb-4.3.orig/include/linux/usb/quirks.h +++ usb-4.3/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 */ Index: usb-4.3/drivers/usb/core/hub.c =================================================================== --- usb-4.3.orig/drivers/usb/core/hub.c +++ usb-4.3/drivers/usb/core/hub.c @@ -124,6 +124,10 @@ struct usb_hub *usb_hub_to_struct_hub(st 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. */ @@ -4503,6 +4507,8 @@ hub_port_init (struct usb_hub *hub, stru 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) { @@ -4701,7 +4707,6 @@ static void hub_port_connect(struct usb_ if (status < 0) goto loop; - usb_detect_quirks(udev); if (udev->quirks & USB_QUIRK_DELAY_INIT) msleep(1000); Index: usb-4.3/drivers/usb/core/quirks.c =================================================================== --- usb-4.3.orig/drivers/usb/core/quirks.c +++ usb-4.3/drivers/usb/core/quirks.c @@ -186,6 +186,12 @@ static const struct usb_device_id usb_qu { 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 */ }; -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
