Skip to contentSkip to conversation

patch "USB: add quirk for devices with broken LPM" added to usb-linus

PATCH [email protected] 1 participant 1 message Dec 11, 2015

Subsystems (2)
Stable branch USB
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

USB: add quirk for devices with broken LPM

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

Quoted 1 line

From ad87e03213b552a5c33d5e1e7a19a73768397010 Mon Sep 17 00:00:00 2001

From: Alan Stern <[email protected]>
Date: Thu, 10 Dec 2015 15:27:21 -0500
Subject: 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 <[email protected]>
Reported-by Steinar H. Gunderson <[email protected]>
Cc stable <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 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(-)
drivers/usb/core/hub.c +6 -1
index 585c3cb07da6..a5cc032ef77a 100644
@@ -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
index fcd6ac0c667f..6dc810bce295 100644
@@ -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
index 9948c874e3f1..1d0043dc34e4 100644
@@ -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 */
Signature · 1 line
2.6.3