[PATCH] Revert "USB / PM: Allow USB devices to remain runtime-suspended when sleeping"

From: Johan Hovold
Date: Mon May 02 2016 - 09:37:55 EST


This reverts commit e3345db85068ddb937fc0ba40dfc39c293dad977, which
broke system resume for a large class of devices.

Devices that after having been reset during resume need to be rebound
due to a missing reset_resume callback, are now left in a suspended
state. This specifically broke resume of common USB-serial devices,
which are now unusable after system suspend (until disconnected and
reconnected) when USB persist is enabled.

During resume, usb_resume_interface will set the needs_binding flag for
such interfaces, but unlike system resume, run-time resume does not
honour it.

Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.5
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---

Greg, Alan,

This patch for v4.6-rc7 fixes a 4.5-regression that broke system suspend
for a large class of devices, including USB-serial devices, for example
when USB persist is enabled.

We may be able to find a way around this, but since it's a user-visible
regression and late in the rc-cycle, I believe reverting the offending
commit is the right thing to do.

Thanks,
Johan


drivers/usb/core/port.c | 6 ------
drivers/usb/core/usb.c | 8 +-------
2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 14718a9ffcfb..460c855be0d0 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -249,18 +249,12 @@ static int usb_port_runtime_suspend(struct device *dev)

return retval;
}
-
-static int usb_port_prepare(struct device *dev)
-{
- return 1;
-}
#endif

static const struct dev_pm_ops usb_port_pm_ops = {
#ifdef CONFIG_PM
.runtime_suspend = usb_port_runtime_suspend,
.runtime_resume = usb_port_runtime_resume,
- .prepare = usb_port_prepare,
#endif
};

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index dcb85e3cd5a7..479187c32571 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -312,13 +312,7 @@ static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)

static int usb_dev_prepare(struct device *dev)
{
- struct usb_device *udev = to_usb_device(dev);
-
- /* Return 0 if the current wakeup setting is wrong, otherwise 1 */
- if (udev->do_remote_wakeup != device_may_wakeup(dev))
- return 0;
-
- return 1;
+ return 0; /* Implement eventually? */
}

static void usb_dev_complete(struct device *dev)
--
2.7.3