Re: [PATCH 4.4 009/115] Bluetooth: btusb: driver to enable the usb-wakeup feature

Brian Norris
2017-12-20T19:56:49Z

+ Kai

One more thing:

On Wed, Dec 20, 2017 at 11:51:14AM -0800, Brian Norris wrote:
> Hi Greg,
>
> On Mon, Dec 18, 2017 at 04:47:58PM +0100, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch. If anyone has any objections, please let me know.
>
> I'm sorry, but I already objected to this one during the discussion
> here:
>
> https://patchwork.kernel.org/patch/10065483/
> [PATCH 4.13 03/28] Bluetooth: btusb: fix QCA Rome suspend/resume
>
> in which we pointed out a regression. The $subject patch does NOT
> actually resolve the previous regression, though it might help to mask
> it. The proper approach to resolve the above regression was to revert
> the patch, not to backport the $subject patch.

We're already working on reverting the above patch to fix the regression
properly:

https://patchwork.kernel.org/patch/10125489/
[PATCH 1/2] Revert "Bluetooth: btusb: fix QCA Rome suspend/resume"

Brian

> Regarding this patch, IIUC this is not a bugfix -- it's a feature
> addition (e.g., for helping with BLE mouse wakeup), and it has already
> been proven to break some user space (we have an internal bug tracking
> this, but suffice it to say that we've already tried and reverted this
> patch [1]). This patch massively increases the surface in which spurious
> bluetooth activity can wake the system, and in some cases we never can
> suspend the system at all.
>
> Unfortunately, Matthias was on vacation when you sent the review
> request, so our team wasn't alerted properly. Can you please back this
> out of all -stable branches?
>
> Or alternatively, if those I've added on CC disagree and are happy to
> deal with the fallout of this patch...well, then that's fine. We can
> revert this patch in our downstream kernels and reapply if/when we can
> account for it properly :)
>
> Thanks,
> Brian
>
> [1]
> https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/750073
>
> > ------------------
> >
> > From: Sukumar Ghorai <sukumar.ghorai@intel.com>
> >
> > commit a0085f2510e8976614ad8f766b209448b385492f upstream.
> >
> > BT-Controller connected as platform non-root-hub device and
> > usb-driver initialize such device with wakeup disabled,
> > Ref. usb_new_device().
> >
> > At present wakeup-capability get enabled by hid-input device from usb
> > function driver(e.g. BT HID device) at runtime. Again some functional
> > driver does not set usb-wakeup capability(e.g LE HID device implement
> > as HID-over-GATT), and can't wakeup the host on USB.
> >
> > Most of the device operation (such as mass storage) initiated from host
> > (except HID) and USB wakeup aligned with host resume procedure. For BT
> > device, usb-wakeup capability need to enable form btusc driver as a
> > generic solution for multiple profile use case and required for USB remote
> > wakeup (in-bus wakeup) while host is suspended. Also usb-wakeup feature
> > need to enable/disable with HCI interface up and down.
> >
> > Signed-off-by: Sukumar Ghorai <sukumar.ghorai@intel.com>
> > Signed-off-by: Amit K Bag <amit.k.bag@intel.com>
> > Acked-by: Oliver Neukum <oneukum@suse.com>
> > Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
> > Cc: Matthias Kaehlcke <mka@chromium.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> > drivers/bluetooth/btusb.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > --- a/drivers/bluetooth/btusb.c
> > +++ b/drivers/bluetooth/btusb.c
> > @@ -1050,6 +1050,10 @@ static int btusb_open(struct hci_dev *hd
> > return err;
> >
> > data->intf->needs_remote_wakeup = 1;
> > + /* device specific wakeup source enabled and required for USB
> > + * remote wakeup while host is suspended
> > + */
> > + device_wakeup_enable(&data->udev->dev);
> >
> > if (test_and_set_bit(BTUSB_INTR_RUNNING, &data->flags))
> > goto done;
> > @@ -1113,6 +1117,7 @@ static int btusb_close(struct hci_dev *h
> > goto failed;
> >
> > data->intf->needs_remote_wakeup = 0;
> > + device_wakeup_disable(&data->udev->dev);
> > usb_autopm_put_interface(data->intf);
> >