Commit ad87e032 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

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: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-by: default avatarSteinar H. Gunderson <sgunderson@bigfoot.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f69115fd

drivers/usb/core/hub.c

+6 −1
Original line number Diff line number Diff line
@@ -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);

drivers/usb/core/quirks.c

+6 −0
Original line number Diff line number Diff line
@@ -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 */

};

include/linux/usb/quirks.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */

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