On Thu, 14 Apr 2016, Matthew Giassa wrote:
> This patch works. Thank you Alan.
>
> What should we do next if I want to push it upstream? Do you propose and
> sign off on it, and I mark it as reviewed?
I don't know about that patch. Other people may object to disabling
LPM for all Point Grey Research cameras, because there's no real
evidence that the cameras don't support LPM properly. All you actually
know is that they don't work well with your program.
Maybe a different approach would be more fruitful. Please try the
patch below instead of the previous one. It tries to avoid disabling
and re-enabling LPM in situations where they shouldn't be necessary.
> Additionally, do you know whom I would CC to propose it gets pushed to
> the current Ubuntu 14.04.4 and Ubuntu 16.04 kernels? I scoured the bug
> report procedures at LaunchPad.net, but couldn't find any useful
> contacts, save for the e-mail addresses of people I pulled from the
> Wily/Xenial git logs.
I have no idea how Ubuntu's internal procedures work.
Alan
Index: usb-4.4/include/linux/usb.h
===================================================================
--- usb-4.4.orig/include/linux/usb.h
+++ usb-4.4/include/linux/usb.h
@@ -1076,7 +1076,7 @@ struct usbdrv_wrap {
* for interfaces bound to this driver.
* @soft_unbind: if set to 1, the USB core will not kill URBs and disable
* endpoints before calling the driver's disconnect method.
- * @disable_hub_initiated_lpm: if set to 0, the USB core will not allow hubs
+ * @disable_hub_initiated_lpm: if set to 1, the USB core will not allow hubs
* to initiate lower power link state transitions when an idle timeout
* occurs. Device-initiated USB 3.0 link PM will still be allowed.
*
Index: usb-4.4/drivers/usb/core/driver.c
===================================================================
--- usb-4.4.orig/drivers/usb/core/driver.c
+++ usb-4.4/drivers/usb/core/driver.c
@@ -284,7 +284,7 @@ static int usb_probe_interface(struct de
struct usb_device *udev = interface_to_usbdev(intf);
const struct usb_device_id *id;
int error = -ENODEV;
- int lpm_disable_error;
+ int lpm_disable_error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
@@ -336,12 +336,14 @@ static int usb_probe_interface(struct de
* setting during probe, that should also be fine. usb_set_interface()
* will attempt to disable LPM, and fail if it can't disable it.
*/
- lpm_disable_error = usb_unlocked_disable_lpm(udev);
- if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
- dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
- __func__, driver->name);
- error = lpm_disable_error;
- goto err;
+ if (driver->disable_hub_initiated_lpm) {
+ lpm_disable_error = usb_unlocked_disable_lpm(udev);
+ if (lpm_disable_error) {
+ dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
+ __func__, driver->name);
+ error = lpm_disable_error;
+ goto err;
+ }
}
/* Carry out a deferred switch to altsetting 0 */
@@ -391,7 +393,8 @@ static int usb_unbind_interface(struct d
struct usb_interface *intf = to_usb_interface(dev);
struct usb_host_endpoint *ep, **eps = NULL;
struct usb_device *udev;
- int i, j, error, r, lpm_disable_error;
+ int i, j, error, r;
+ int lpm_disable_error = -ENODEV;
intf->condition = USB_INTERFACE_UNBINDING;
@@ -399,12 +402,13 @@ static int usb_unbind_interface(struct d
udev = interface_to_usbdev(intf);
error = usb_autoresume_device(udev);
- /* Hub-initiated LPM policy may change, so attempt to disable LPM until
+ /* If hub-initiated LPM policy may change, attempt to disable LPM until
* the driver is unbound. If LPM isn't disabled, that's fine because it
* wouldn't be enabled unless all the bound interfaces supported
* hub-initiated LPM.
*/
- lpm_disable_error = usb_unlocked_disable_lpm(udev);
+ if (driver->disable_hub_initiated_lpm)
+ lpm_disable_error = usb_unlocked_disable_lpm(udev);
/*
* Terminate all URBs for this interface unless the driver
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
